Common Tickborne Illnesses

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Common Tickborne Illnesses DIAGNOSIS AND MANAGEMENT Daniel Stephen Cervonka, DHSc, CAS, PA-C

The deer tick carries Borrelia burgdorferi, the Lyme disease–causing spirochete.

With the arrival of warmer weather, tick bites and tickborne illness trigger renewed confusion regarding antibiotic prophylaxis, treatment regimens for documented tickborne illness—and even the best way to remove a tick. Here is a sensible approach to Lyme disease, Rocky Mountain spotted fever, and ehrlichiosis.

CONTINUING EDUCATION INFORMATION TARGET AUDIENCE: This activity has been designed to meet the educational needs of physicians, physician assistants, and nurse practitioners involved in the management of patients who may have been exposed to a tickborne infection. • Original Release Date: April 2009 • Expiration Date: April 30, 2010 • Estimated Time to Complete This Activity: 1 hour • Medium: Printed journal and online CME • Sponsored by Postgraduate Institute for Medicine PROGRAM OVERVIEW: The primary objective of this educational initiative is to provide clinicians in primary care with the most up-to-date information regarding the transmission, diagnosis, and management of three common tickborne illnesses. EDUCATIONAL OBJECTIVES: After completing this activity, the participant should be better able to: • Explain the safest strategy for tick removal. • Describe signs and symptoms that help the clinician identify Lyme disease, Rocky Mountain spotted fever, and ehrlichiosis. • Identify disease-specific laboratory tests for detection of these three common tickborne illnesses. • Specify current recommendations for infection prophylaxis and treatment of documented tickborne disease. FACULTY: Daniel Stephen Cervonka, DHSc, CAS, PA-C , is Senior Physician Associate in on-site medicine and psychiatry at Yale–New Haven Hospital in New Haven, Connecticut. PHYSICIANS Accreditation Statement: This activity has been planned and implemented in accordance with the Essential Areas and Policies of the Accreditation Council for Continuing Medical Education (ACCME) through the joint sponsorship of Postgraduate Institute for Medicine (PIM) and Quadrant HealthCom Inc. PIM is accredited by the ACCME to provide continuing medical education for physicians. Credit Designation: Postgraduate Institute for Medicine designates this educational activity for a maximum

of 1.0 AMA PRA Category 1 CreditTM. Physicians should only claim credit commensurate with the extent of their participation in the activity. PHYSICIAN ASSISTANTS The American Academy of Physician Assistants accepts AMA category 1 credit for the PRA from organizations accredited by ACCME. NURSE PRACTITIONERS This program has been approved by the Nurse Practitioner Association New York State (The NPA) for 1.0 contact hour. DISCLOSURE OF CONFLICTS OF INTEREST: Postgraduate Institute for Medicine (PIM) assesses conflict of interest with its instructors, planners, and managers, and other individuals who are in a position to control the content of CME activities. All relevant conflicts of interest that are identified are thoroughly vetted by PIM for fair balance, scientific objectivity of studies utilized in this activity, and patient care recommendations. PIM is committed to providing its learners with high-quality CME activities and related materials that promote improvements or quality in health care and not a specific proprietary business interest of a commercial interest. The faculty reported the following financial relationships or relationships to products or devices they or their spouse/life partner have with commercial interests related to the content of this CME activity: Daniel Stephen Cervonka, DHSc, CAS, PA-C, reported no significant financial relationship with any commercial entity related to this activity. The planners and managers reported the following financial relationships or relationships to products or devices they or their spouse/life partner have with commercial interests related to the content of this CME activity: Jan Hixon, RN, BSN, MA, Linda Graham, RN, BSN, BA, and Trace Hutchison, PharmD, reported no significant financial relationship with any commercial entity related to this activity. METHOD OF PARTICIPATION: The fee for participating and receiving CME credit for this activity is

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$10.00. During the period April 2009 through April 30, 2010, participants must 1) read the learning objectives and faculty disclosures; 2) study the educational activity; 3) complete the posttest by recording the best answer to each question in the answer key on the evaluation form on page 25; 4) complete the evaluation form; and 5) mail or fax the evaluation form with answer key and payment or payment information to: Postgraduate Institute for Medicine, 367 Inverness Parkway, Suite 215, Englewood, CO 80112; fax: (303) 790-4876. This test can also be taken online at www.Clinicians CME.com. If you have any questions, call (800) 4233576 or e-mail [email protected]. A statement of credit will be issued only upon receipt of a completed activity evaluation form and a completed posttest with a score of 70% or better. Your statement of credit will be mailed to you within three weeks. DISCLOSURE OF UNLABELED USE: This educational activity may contain discussion of published and/or investigational uses of agents that are not indicated by the FDA. Postgraduate Institute for Medicine (PIM), The NPA, and Quadrant HealthCom Inc. do not recommend the use of any agent outside of the labeled indications. The opinions expressed in this educational activity are those of the faculty and do not necessarily represent the views of PIM, The NPA, or Quadrant HealthCom Inc. Please refer to the official prescribing information for each product for discussion of approved indications, contraindications, and warnings. DISCLAIMER: Participants have an implied responsibility to use the newly acquired information to enhance patient outcomes and their own professional development. The information presented in this activity is not meant to serve as a guideline for patient management. Any procedures, medications, or other courses of diagnosis or treatment discussed or suggested in this activity should not be used by clinicians without evaluation of their patient’s conditions and the possible contraindications or dangers in use, review of any applicable manufacturer’s product information, and comparison with recommendations of other authorities.

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mong the many seasonal illnesses seen by primary care clinicians, Lyme disease, Rocky Mountain spotted fever (RMSF), and ehrlichiosis are among the more challenging diagnoses. From 1992 to 2006, 248,074 cases of Lyme disease were reported to the CDC by health departments in the 50 states, with a 101% increase from 1992 (9,908 cases) to 2006 (19,931 cases).1 Among children and young men, the increased incidence is considered “disproportionate.” Left untreated, Lyme disease can lead to conditions that include arthritis, carditis, and neurologic deficits. Its continuing emergence, CDC researchers note, underscores the importance of standardized reporting in a “sustainable” surveillance system, targeted prevention strategies, and early disease recognition and treatment.1 Since the 1940s, between 250 and 1,200 cases of RMSF have been reported each year to the CDC by local health departments.2 Many cases are believed to go unreported, and the importance of a consistent case definition to standardize reporting is emphasized by the CDC. If treatment is not begun within a few days of illness onset, severe illness or even death may result—particularly in children.3 As recently as 2008, efforts have been made by the CDC to improve categorization and surveillance of ehrlichiosis,4 which encompasses human monocytic ehrlichiosis and human granulocytic anaplasmosis (conditions with similar clinical manifestations).5,6 In the period of 2001 to 2002, 1,176 cases of these two illnesses and 29 cases of “other ehrlichioses” were reported to the CDC by 32 states through the National Electronic Telecommunications System for Surveillance,

TABLE 1

Three Common Tickborne Illnesses: Etiology and Epidemiology1,3,7-9 Greatest regional distribution (US)

Seasonal occurrencea

Borrelia burgdorferi

Connecticut, Delaware, Maryland, Massachusetts, Minnesota, New Jersey, New York, Pennslyvania, Rhode Island, Wisconsin

June – August

Rickettsia rickettsii

Highest incidenceb in Arkansas, Missouri, North Carolina, Oklahoma, South Carolina; next,c Mississippi, Tennessee, Wyoming

April – September

Ehrlichia chaffeensis

Missouri, Oklahoma

April – October

Ehrlichia ewingii

Tennessee, Rhode Island

Known tick vectors

Etiologic agents

Lyme disease

Deer tick, blacklegged tick (Ixodes scapularis, Ixodes pacificus)

Rocky Mountain spotted fever

American dog tick (Dermacentor variabilis) Rocky Mountain wood tick (Dermacentor andersoni) Common brown dog tick (Rhipicephalus sanguineus)

Human ehrlichiosis

Lone star tick (Amblyomma americanum)

Anaplasma phagocytophilum

Tennessee, Illinois, Wisconsind

Data extracted from: Bacon et al. MMWR Surveill Summ. 20081; CDC. MMWR Morb Mortal Wkly Rep. 20078; Amitai and Sinert. www.emedicine.com/EMERG/topic510.htm. 20069; CDC. MMWR Morb Mortal Wkly Rep. 20003; Demma et al. Am J Trop Med Hyg. 2005.7 a

Cases can be contracted at almost any time of year in the United States

b

15 or more cases per million population annually

c

10 to 14.9 cases per million population annually

d

Regional incidence data reported separately for human monocytic ehrlichiosis, human granulocytic anaplasmosis, and “other ehrlichioses,” respectively

with 883 and 106 additional cases, respectively, reported through a passive surveillance system of tickborne disease.7 According to Demma et al,7 occurrence of these conditions is probably significantly underreported. For etiologic and epidemiologic information about Lyme disease, RMSF, and ehrlichiosis, see Table 1.1,3,7-9 Making the diagnosis of any one of these tickborne illnesses can be difficult. The sage advice of eliciting a good history and physical examination and of initiating the correct laboratory evaluation should, in most cases, yield the correct diagnosis.

Daniel Stephen Cervonka is Senior Physician Associate in on-site medicine and psychiatry at Yale–New Haven Hospital in New Haven.

TICKS AND ASSOCIATED PATHOGENS

Ticks are classified based on the outer body shell: those with a hard shell (Ixodes species) are the more common human-biting ticks. According to Amitai and Sinert,9 the American dog tick and the Rocky mountain wood tick most often serve as the vector and reservoir for RMSF, although one outbreak in Arizona was linked to the common brown dog tick. The pathogens associated with ehrlichiosis are carried by the lone star tick.5 When a tick bites, it cuts into the epidermal layer of the skin and secretes a cementing agent with its saliva, using the hypostome (mouthparts). While it is


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attached to the epidermis, the hypostome periodically releases saliva mixed with the cement so that it can continue feeding while remaining attached.10 During the feeding cycle, the tick continues to secrete an anti-inflammatory substance and an anticoagulant.11 When feeding on an infected host, the tick ingests pathogens into the midgut, where they are safe from destruction. The pathogens then migrate into the salivary glands and hypostome; from there, they can be transmitted to another host during a subsequent feeding.12 Distressing as a tick bite can be, a far greater concern is whether the tick is carrying any of the organisms responcontinued on next page >>

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Common Tickborne Illnesses

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The Scutal Index15 One challenge a clinician may face is to determine the length of time an embedded tick has been feeding on the host patient. Currently, the most logical method is to track the patient’s recent activities and determine when he or she was at greatest risk for tick bite. This crude method can be fairly effective, but it is certainly not 100% accurate. Meiners et al15 have published research regarding use of the scutal index (see figure) to determine duration of attachment to the host. This index is a ratio of the length of the lower part of the body of the tick, the abdomen, a which expands during feeding (a), b divided by the width of the upper body (b), the scutum, which remains constant during feeding; a result greater than 1.1 indicates that the time attached is longer than 24 hours. Scutal Index = a/b The researchers found that the level of engorgement reflected the duration of feeding time; in ticks that had been feeding for 12 to 24 hours, the scutal index was found to be statistically significantly higher than in ticks with shorter feeding times. To obtain the necessary measurements requires a stereoscope with a micrometer, which may be available in the emergency setting. The figure above depicts the tick scutal index (a/b), as described by Meiners et al. Int J Med Microbiol. 2006.15 Figure adapted with Dr. Meiners’ permission.

sible for Lyme disease, RMSF, or ehrlichiosis—and whether one of these pathogens is transmitted during a feeding. It is believed that a tick must feed for at least 24 hours in order to transmit a disease-carrying organism, and the feeding cycle of an Ixodes tick can last for days.13,14 Identifying a tick that has bitten a human patient and determining how long the tick was attached are important predictors of potential illness (see “The Scutal Index,”15 above) and should guide the clinician’s course of action.6 Patient presentation, common physical findings, diagnosis, and management of the three tickborne diseases that are most common in the US will be discussed.

POSSIBLE PATIENT PRESENTATIONS

Among patients affected by tickborne disease, three presentations are most typically seen by the primary care clinician. The first, most common, and least difficult to manage is a recent tick bite,

with the tick still embedded into the skin (see “Tick Removal,” below). The predominant clinical questions are how to remove the tick and whether to prescribe antibiotics. In the second type of presentation, the patient has attempted to remove the tick, with mouthparts retained in the skin. How to remove the retained parts and whether to prescribe antibiotics are the most important considerations. The final and most challenging presentation is that of the patient who presents during warm weather with any of the following symptoms: unrelenting headache, fever, rash, myalgia, and arthralgia—with or without awareness of a tick bite. Clinicians need to maintain a high index of suspicion for tickborne illness when they see such patients.

diately—or at least within 24 hours (after which transmission of a pathogen is considered most likely13,14). For ticks known to communicate disease in the US, the best method of removal is with fine-tipped tweezers, small forceps, or a notched tick extractor. Firmly grasp the tick, very close to the skin, and draw it away with a steady motion.16,17 Mouthparts, if left behind, can also be removed with the tweezers. The area should then be disinfected and the hands washed with soap and water. Other “folklore remedies” for removing ticks (eg, burning or applying lidocaine, petroleum jelly, kerosene, or gasoline) have been reported ineffective.16,17 Use of soap, heat, or other irritants (or twisting or crushing the body of the tick while removing it) may cause the tick to release additional saliva, increasing the risk of disease transmission.16

PHYSICAL EXAMINATION

Generally, any patient who presents with the aforementioned symptoms (persistent headache, fever, rash, myalgia, arthralgia) should undergo a general physical examination with close attention to the skin and scalp, and to the neurologic and musculoskeletal components. In patients who pre sent with a tick embedded in the skin or with retained mouthparts, the clinician should carefully inspect the surrounding area (after removal) for erythema or other signs of infection.

an incubation period of seven days to one month20 (see Figure 1, page 23). In most cases, the EM rash appears between days 7 and 10 and can expand at a rate of 2.0 cm per day. In early localized Lyme disease, a single EM lesion can expand centrally from the site of the bite, but in early disseminated Lyme disease, several lesions may be present.21,22 Multiple-lesion EM, with neither the classic central clearing or bull’s-eye appearance, indicates hematogenous spread of the disease. The EM rash can resolve spontaneously. In the patient with RMSF, the characteristic rash (ie, converting from a blanching macular rash to a petechial rash6) is considered diagnostic; it has been reported in more than 90% of patients9 (see Figure 2, page 23). This rash appears about five days after disease onset, most commonly developing on the patient’s wrists and ankles, then spreading to the trunk, the palms of the hands, and the soles of the feet as the disease progresses.6,9 Ehrlichiosis can present with a maculopapular rash (often on the trunk rather than the site of the tick bite6), but this diagnostic sign is reported in only 6% of cases during the early stage of infection. After the first week of infection, the rash is present in about 25% of the cases and can be macular, maculopapular, or petechial. The rash can also be transient.23

Neurologic Headache is the most common Skin symptom in all three diseases, Examination of the skin and scalp but its presentation varies. In is particularly important when Lyme disease, headache does not tickborne illness is a consider- usually develop until the infecation. In Lyme disease, the most tion has disseminated; disseminacommon of the three conditions, tion into the cerebrospinal fluid is the classic early presentation is most commonly found in patients the erythema migrans (EM) rash. who also experience photophobia Tick Removal This rash, classically described as combined with nuchal rigidity.22 In the event that a patient does a “bull’s-eye” rash,18,19 presents in Typically, headache associated discover a tick attached to his or 70% to 80% of patients with with Lyme disease presents with skin, it should be removed imme- Lyme disease1 and develops after fever. Clinician Reviews April 2009 • Vol 19, No 4

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Bell’s palsy can be a confusing comorbidity. In one small study, eight of 32 patients who had Bell’s palsy had positive results on serologic testing for Lyme disease.24 In most cases of RMSF and ehrlichiosis, headache is accompanied by fever.23 In fact, in patients with RMSF, headache with fever can indicate that the infection has progressed to greater numbers of the pathogen dividing in the microvasculature, leading to clotting and inflammation.25

Musculoskeletal The musculoskeletal examination is especially important when the patient complains of myalgia and arthralgia. Myalgia is reported to be common in early-stage Lyme disease,26 in addition to early presentations of ehrlichiosis or RMSF.23,25 Arthritis appears to be a development that is restricted to untreated, late-disseminated Lyme disease.20 Lyme-associated arthritis, which is not a destructive entity, can present in any joint but is most common in the knee, often with disproportionate swelling.27,28 Symptoms can present as monoarthritis or polyarthritis and can be chronic or intermittent.

LABORATORY WORKUP

The laboratory evaluation for suspected tickborne illness is facilitated by the careful history. An understanding of the relevant epidemiology is crucial (ie, assurance that the illness in question is endemic for the area of practice or patient travel; the possibility of tick exposure; onset of symptoms during the relevant time period).1,29 In general, a complete blood count (CBC), platelet count, and erythrocyte sedimentation rate (ESR) are obtained initially. Abnormal laboratory results associated with each of the three diseases are shown in Table 25,9,28 (see page 24). The CBC, platelet count, and ESR are helpful but not diagnos-

tic. In the evaluation for illness suspected to be Lyme disease, RMSF, or ehrlichiosis, the correct diagnosis depends on specific studies (possible results of which are included in Table 2). For Lyme disease, a polyvalent enzyme-linked immunosorbent assay (ELISA) is usually the first disease-specific test performed. If results are positive or uncertain, immunoglobulin M (IgM) and IgG immunoblots should be performed separately, using the same serum sample.12,30 Use of polymerase chain reaction (PCR) or culture of skin or blood specimens in patients with EM is considered expensive and inconvenient.12 For the identification of RMSF, the immunofluorescent antibody (IFA) test for detection of Rickettsia rickettsii is more than 90% sensitive. IFA is considered the primary means for diagnosing this disease.25 Ehrlichiosis is diagnosed using serology and PCR techniques (to amplify the ehrlichial DNA). Isolating the responsible pathogen is the most direct and reliable process. However, because this is labor- and time-intensive and thus expensive, it is rarely employed.31 Careful consideration should be given to the pathogen’s potential for causing illness when the laboratory evaluation is ordered. Prophylaxis during the wait for test results may be appropriate.

FIGURE 1 The pathognomonic erythematous rash (in “bull’s-eye” pattern) often seen in patients with a Lyme disease–associated tick bite. Source: the CDC Public Health Image Library.

made after a careful history and

tis should be considered, as should

FIGURE 2 A child’s right hand and wrist displaying the spotted rash characteristic of Rocky Mountain spotted fever. Source: the CDC Public Health Image Library.

DIFFERENTIAL DIAGNOSIS

Making the diagnosis of any of the tickborne illnesses discussed here presents a considerable challenge. Lyme disease, for example, has been called the “latest great imitator”—and for good reason.32 In the early stage of Lyme disease, the classic EM rash can mimic a spider bite, a viral exanthema, or even hives. In the early and late disseminated stages, the differential can be expanded to include arthritis, migraine headache, neuritis, and chronic musculoskeletal pain.33 The diagnosis can only be

physical examination, including recent travel and activity in wooded areas. An understanding of the tickborne pathogens that are endemic to the area of practice or patient travel is also necessary. Diagnosing RMSF is another clinical challenge, and undetected RMSF can be fatal. As stated earlier, the classic rash is the most common clue. Other considerations, such as early disseminated intravascular coagulation and vasculi-


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certain viral illnesses. Serologic IFA is less sensitive than direct immunofluorescence through punch biopsy; a negative IFA result does not entirely rule out RMSF.3,34 Putting together the clinical picture is key. Unlike the two other illnesses, Ehrlichia infection is a subclinical disease that often goes undetected; it can also be difficult to distinguish from Lyme disease. It has been continued on next page >>

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TABLE 2

Abnormal Laboratory Results Associated With Common Tickborne Illnesses5,9,28 Test

Lyme disease

RMSF

Human ehrlichiosis

CBC

Normal

Leukocytosis but nonspecific

Leukocytosis, neutropenia, lymphocytopenia, thrombocytopenia

Platelet count

Normal

Thrombocytopenia in 50% of patients

Thrombocytopenia

ESR

Normal

Elevated and nonspecific

Elevated and nonspecific

Disease-specific tests and other results

Lyme ELISA; if positive, then Western blot (more sensitive)

Elevated IFA result is 94% to 100% sensitive; Na level helpful since 30% of patients are hyponatremic

Mild AST/ALT elevations; elevated IFA, elevated IgG

Abbreviations: RMSF, Rocky Mountain spotted fever; CBC, complete blood count; ESR, erythrocyte sedimentation rate; ELISA, enzyme-linked immunosorbent assay; IFA, immunofluorescent assay; AST, aspartate aminotransferase; ALT, alanine aminotransferase; Na, sodium; IgG, immunoglobulin G. Data extracted from: Cunha. www.emedicine.com/med/topic3391.htm. 20085; Amitai and Sinert. www.emedicine.com/EMERG/topic510.htm. 20069; Edlow. Tick-borne diseases: Lyme (2008). www.emedicine.com/emerg/topic588.htm.28

suggested that one patient in five with a diagnosis of Lyme disease may be coinfected with ehrlichiosis—a reminder that these illnesses are not mutually exclusive.35 Making a diagnosis of ehrlichiosis is based on consideration of the pathogen and its potential in the geographic region, with the laboratory evaluation possibly yielding important clues. Persistent myalgias in the setting of leukocytosis, thrombocytopenia, and negative test results for Lyme disease should alert the clinician to order IFA for Ehrlichia. Similarly, patients who have been given a diagnosis of RMSF with no rash should be tested for ehrlichiosis.5

PHARMACOLOGIC MANAGEMENT

Until recently, pharmacologic management of Lyme disease was a source of controversy. In 1996, results of a meta-analysis that examined antibiotic prophylaxis for tick-bitten patients were inconclusive.36 In 2001, it was reported that a single 200-mg dose of doxycycline within 72 hours of a tick bite effectively prevented Lyme disease.37 Guidelines published in 2006

by the Infectious Diseases Society of America12 upheld this strategy for adults and children 8 and older (with dosing for children at 4 mg/kg; maximum dose, 200 mg), but only under all of the following circumstances: • The tick can be reliably identified as an adult or nymphal Ixodes scapularis tick that has been attached for at least 36 hours, based on estimated time of exposure or degree of engorgement of the tick. • Chemoprophylaxis can be initiated within 72 hours of the tick’s removal (as no data are available to confirm its effectiveness beyond 72 hours). • At least 20% of ticks in the area are known to be infected with Borrelia burgdorferi. • Treatment with doxycycline treatment is not contraindicated.12 These guidelines offer clinicians good direction regarding infection prophylaxis following a confirmed bite by a Lyme disease–associated tick. Prophylaxis against RMSF or ehrlichiosis after a tick bite is not supported in the literature.9,38 As for treatment of confirmed

Lyme disease, RMSF, or ehrlichiosis, first-line therapy consists of twice-daily doxycycline 100 to 200 mg by mouth for 14 to 21 days.1,5,9,39,40 Amoxicillin and cef uroxime are considered alternative therapeutic options for early localized or early disseminated Lyme disease.1,12 Almost regardless of the patient’s age, doxycycline is the drug of choice for treatment of confirmed RMSF. In patients who are hypersensitive to doxycycline, chloramphenicol (500 mg IV divided, four times a day for seven days) is an alternative treatment. It should be used only if the anticipated benefits outweigh the risks.9,39 Chloramphenicol is not considered effective for patients with ehrlichiosis.5 Limited evidence supports the use of rifampin or one of the fluoroquinolones in patients with ehrlichiosis who cannot take doxycycline (including pregnant or breastfeeding women and children younger than 8).6,12,41,42

PATIENT EDUCATION

Tick bites can often be prevented with a few simple precautions. Contrary to myth, ticks do not jump onto human hosts or drop on


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them from overhead; rather, they brush onto hosts passing by them in tall grass or leaf litter. Patients should be advised to avoid areas known to be tick infested, to wear clothing that minimizes exposed skin when they spend time in areas where ticks may be present (and light-colored clothing is recommended to facilitate tick detection), and to check thoroughly for ticks after they return home.43,44 Additionally, the insect repellent DEET (N,N-diethyl-3methyltoluamide, 20% to 30%) is widely recommended for repelling ticks43; other agents approved by the Environmental Protection Agency for application to the skin include picaridin and oil of lemon eucalyptus.45 For additional protection, repellents containing permethrin may be applied to clothing only; contact with the skin must be avoided.43

CONCLUSION

For many patients, tick bites can be a frightening prospect. Considering the past confusion about chemoprophylaxis and treatment for the resulting illnesses, they are of concern to clinicians as well. It is important to understand the potential for tickborne disease and the epidemiology of related pathogens in one’s practice area. Recognizing the signs and symptoms of Lyme disease, RMSF, or ehrlichiosis is the next step to early, effective treatment—which is readily available and relatively inexpensive. Proper history and physical examination, combined with appropriate laboratory testing, will help the clinician make the diagnosis. Until the unlikely possibility that tickborne illness is eradicated, primary care providers are called on to educate patients to avoid tick bites and remain vigilant to the possibility of tickborne illness. CR

REFERENCES

1. Bacon RM, Kugeler KJ, Mead PS; Centers for Disease Control and Prevention. Surveillance for Lyme disease—United States, 1992-2006. MMWR Surveill Summ. 2008;57(10):1-9.

2. Centers for Disease Control and Prevention. Tickborne rickettsial diseases: statistics. www.cdc .gov/ticks/diseases/rocky_mountain_spotted_ fever/statistics.html. Accessed March 27, 2009. 3. Centers for Disease Control and Prevention. Consequences of delayed diagnosis of Rocky Mountain spotted fever in children—West Virginia, Michigan, Tennessee, and Oklahoma, May– July 2000. MMWR Morb Mortal Wkly Rep. 2000;49(39):885-888. 4. Centers for Disease Control and Prevention. Notice to readers: changes to MMWR table I and presentation of National Notifiable Diseases Surveillance System data—January 2008. MMWR

Morb Mortal Wkly Rep. 2008;57(01);14. 5. Cunha BA. Ehrlichiosis (2008). www.emedi cine.com/med/topic3391.htm. Accessed March 27, 2009. 6. Gayle A, Ringdahl E. Tick-borne diseases. Am Fam Physician. 2001;64(3):461-466. 7. Demma LJ, Holman RC, McQuiston JH, et al. Epidemiology of human ehrlichiosis and anaplasmosis in the United States, 2001-2002. Am J Trop Med Hyg. 2005;73(2):400-409. 8. Centers for Disease Control and Prevention. Lyme disease—United States, 2003-2005. MMWR Morb Mortal Wkly Rep. 2007;56(23):573576.

Posttest Questions 1. A “disproportionate” increase in the incidence of Lyme disease has been reported among: a. Women and children b. Elderly patients c. Residents of North Carolina and South Carolina d. Children and young men 2. Carditis and neurologic deficits may develop in patients with untreated: a. Human granulocytic anaplasmosis b. Human monocytic ehrlichiosis c. Lyme disease d. Rocky Mountain spotted fever (RMSF) 3. The known vectors for Borrelia burgdorferi, the pathogen known to cause Lyme disease, are: a. The lone star tick and the common brown dog tick b. The black-legged tick and the lone star tick c. The deer tick and the black-legged tick d. The American dog tick and the deer tick 4. Which of the following is the preferred strategy to remove a tick? a. Crush the body of the tick with small pliers or forceps, then remove it b. Firmly grasp the tick with tweezers or forceps, very close to the skin, and draw it away with a steady motion c. Apply soap, lidocaine, or petroleum jelly to debilitate the tick, then remove it d. Apply a lit match to the body of the tick to kill it, then remove it 5. The rash considered diagnostic of RMSF: a. Converts from a blanching macular rash to a petechial rash b. First appears on the patient’s trunk c. Occurs in about 75% of patients d. Is classically described as a “bull’s-eye” rash 6. The headache associated with Lyme disease: a. Usually develops during the early localized stage b. Is most often found in afebrile patients c. Suggests disseminated infection and may occur with photophobia and nuchal rigidity d. Usually precedes the development of Bell’s palsy 7. Which of the following is more than 90% sensitive for diagnosis of RMSF? a. An immunofluorescent antibody (IFA) test that detects Rickettsia rickettsii b. Polymerase chain reaction (PCR) for amplification of Anaplasma phagocytophilum DNA c. A polyvalent enzyme-linked immunosorbent assay (ELISA) d. A finding of thrombocytopenia on the platelet count

9. Amitai A, Sinert R. Tick-borne diseases: Rocky Mountain spotted fever (2006). www.emedicine .com/EMERG/topic510.htm. Accessed March 27, 2009. 10. Anderson JF. The natural history of ticks. Med Clin North Am. 2002;86(2):205-218. 11. Wikel SK. Host immunity to ticks. Annu Rev Entomol. 1996;41:1-22. 12. Wormser GP, Dattwyler RJ, Shapiro ED, et al. The clinical assessment, treatment, and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America. Clin Infect Dis. 2006;43(9):1089-1134.

Examination Answer Sheet

Issue Date: April 2009 Expiration Date: April 30, 2010 This exam can be taken online at www.CliniciansCME.com. Upon passing the exam, you can print out your certificate immediately. You can also view your test history at any time and print out duplicate certificates from the Web site.

Common Tickborne Illnesses Directions: Select one answer for each question in the exam and evaluation by completely darkening the appropriate circle. An identifier is required to process your exam. The primary objective of this educational initiative is to provide clinicians in primary care with the most up-to-date information regarding the transmission, diagnosis, and management of three common tickborne illnesses.

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1 = Very well 2 = Well 3 = Fairly 4 = Poorly 5 = Very poorly How well was each course objective met? 11. Explain the safest strategy for tick removal. 12. Describe signs and symptoms that help the clinician identify Lyme disease, Rocky Mountain spotted fever, and ehrlichiosis. 13. Identify disease-specific laboratory tests for detection of these three common tickborne illnesses. 14. Specify current recommendations for infection prophylaxis and treatment of documented tickborne disease.

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1 = Very well 2 = Well 3 = Fairly 4 = Poorly 5 = Very poorly Rate the effectiveness of how well the activity: 15. Related to your practice needs. 1 16. Will help you improve patient care. 1 17. Avoided commercial bias/influence. 1 18. How would you rate the overall quality of the material presented? 1 19. Your knowledge of the subject was increased: Greatly Somewhat Hardly 20. The difficulty of the course was: Complex Appropriate Basic How long did it take to complete this course? Suggested topics for future CE articles:

Comments on this course: Please retain a copy for your records. Please print clearly.

You must choose and complete one of the following three identifier types:

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8. According to 2006 guidelines published by the Infectious Diseases Society of America, criteria for use of doxycycline as prophylaxis against Lyme disease include: a. Contraindications for chloramphenicol b. Evidence that at least 50% of ticks in the given area are infected with B burgdorferi c. Attachment to the patient of an adult or nymphal Ixodes scapularis tick for at least 36 hours d. Availability of chemoprophylaxis within 12 hours of the tick’s removal

9. For patients with confirmed early localized or early disseminated Lyme disease and contraindications for taking doxycycline, an alternate therapeutic choice is: a. Amoxicillin or cefuroxime c. A fluoroquinolone b. Chloramphenicol d. Rifampin

Business Name

10. Which of the following tick repellents is not approved by the Environmental Protection Agency for application to the skin? a. DEET (N,N-diethyl-3-methyltoluamide, 20% to 30%) b. Permethrin c. Picaridin d. Oil of lemon eucalyptus

13. Smith-Fiola D; National Ag Safety Database. Protect yourself from ticks and Lyme disease. www.cdc.gov/nasd/docs/d000901-d001000/ d000961/d000961.html. Accessed March 27, 2009. 14. des Vignes F, Piesman J, Heffernan J, et al. Effect of tick removal on transmission of Borrelia burgdorferi and Ehrlichia phagocytophila by Ixodes scapularis nymphs. J Infect Dis. 2001;183(5): 773-778. 15. Meiners T, Hammer B, Gobel UB, Kahl O. Determining the tick scutal index allows assessment of tick feeding duration and estimation of continued on next page >>

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Lesson 106092


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6442-ED-34

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CLR0904

DERMADiagnosis Joe R. Monroe, PA-C, MPAS

A

14-year-old boy presents for evaluation of a longstanding condition involving loss of pigment of the hair and the adjacent neck skin. This discoloration has been present since shortly after his birth. The patient is specifically interested in treatment options. His history includes a diagnosis of tuberous sclerosis, which he received at an early age. On examination, you note a complete loss of pigment in the posterior scalp on the patient’s left side, along with total loss of color in the skin on the adjacent part of the neck. The medial margins of both stop abruptly at midline. Additional inspection reveals several other abnormalities, including dart-shaped hypopigmented macules on the patient’s trunk, fleshy 1- to Joe R. Monroe is a PA at Regional Dermatology Clinic, Bartlesville, Oklahoma. He is also the founder of the Society of Dermatology Physician Assistants.

CE

3-mm papules clustered about the midface, and periungual fibromatous papules around several toenails.

ples, as opposed to the sharply demarcated areas of complete color loss seen in poliosis. Poliosis can be seen as a feature of vitiligo (choice “c”), but the latter usually also involves pigment loss elsewhere.

All of these findings support the diagnosis of tuberous sclerosis, as does the focal loss of scalp hair color, which is known as: a) “Graying” b) Hypomelanosis c) Vitiligo d) Poliosis

DISCUSSION/TREATMENT

ANSWER

The correct answer is poliosis (choice “d”), which has been described as a reliable indicator of tuberous sclerosis when seen early in life.1 Poliosis is the specific term for focal loss of color in scalp hair. Technically, this process is a form of hypomelanosis (choice “b”), although the lat-

ter is a more generic term used to refer to loss of pigment in any area. Graying (choice “a”) usually refers to uniform loss of hair color all over the scalp—albeit with focal accentuation over the tem-

Poliosis, which is often idiopathic, can be seen in a number of conditions besides tuberous sclerosis and vitiligo, including halo nevi of the scalp, alopecia areata (as hair regrows), and Waardenburg’s syndrome. As mentioned above, it can appear early in life as an indicator of tuberous sclerosis, particularly when coupled with involvement of adjacent dermatomal skin. This was likely the case with this patient. No permanent treatment exists for this problem. CR

REFERENCE

1. Apibal Y, Reakatanan W, Chunharas A . Poliosis as the first clue of tuberous sclerosis. Pediatr Dermatol. 2008;25(4):486-487.



infection risk with Borrelia burgdorferi sensu lato in a person bitten by an Ixodes ricinus nymph. Int J Med Microbiol. 2006;296 Suppl 40:103-107. 16. Gammons M, Salam G. Tick removal. Am Fam Physician. 2002;66(4):643-645. 17. Pitches DW. Removal of ticks: a review of the literature. Euro Surveill. 2006;11(8):E060817.4. 18. Taege AJ. Tick trouble: overview of tick-borne diseases. Cleve Clin J Med. 2000;67(4):241, 245249. 19. Murray T, Feder HM Jr. Management of tick bites and early Lyme disease: a survey of Connecticut physicians. Pediatrics. 2001;108(6): 1367-1370. 20. Flicek BF. Rickettsial and other tick-borne infections. Crit Care Nurs Clin North Am. 2007; 19(1):27-38. 21. Edlow JA. Lyme disease and related tick-borne illnesses. Ann Emerg Med. 1999;33(6):680-693. 22. Moses JM, Riseberg RS, Mansbach JM. Lyme disease presenting with persistent headache. Pediatrics. 2003;112(6 Pt 1):e477-e479. 23. Olano JP, Walker DH. Human ehrlichioses. Med Clin North Am. 2002;86(2):375-392. 24. Halperin JJ, Golightly M; Long Island Neuroborreliosis Collaborative Study Group. Lyme borreliosis in Bell’s palsy. Neurology. 1992;42(7):1268-1270. 25. Sexton DJ, Kaye KS. Rocky mountain spotted

fever. Med Clin North Am. 2002;86(2):351-360. 26. Bachur R, Harper M. Lyme disease (2006). w w w.emedicine.com / PED/topic1331.htm. Accessed March 27, 2009. 27. Meyerhoff JO. Lyme disease (2008). www .emedicine.com/med/topic1346.htm. Accessed March 27, 2009. 28. Edlow JA. Tick-borne diseases: Lyme (2008). www.emedicine.com/emerg/topic588.htm. Accessed March 27, 2009. 29. Edlow JA. Erythema migrans. Med Clin North Am. 2002;86(2):239-260. 30. Centers for Disease Control and Prevention. Recommendations for test performance and interpretation from the Second National Conference on Serologic Diagnosis of Lyme Disease. MMWR Morb Mortal Wky Rep. 1995;44(31):590-591. 31. Centers for Disease Control and Prevention. Human ehrlichiosis in the United States: laboratory detection (2000). www.cdc.gov/ncidod/dvrd/ ehrlichia/Laboratory/Laboratory.htm. Accessed March 27, 2009. 32. Stechenberg BW. Lyme disease: the latest great imitator. Pediatr Infect Dis J. 1988:7(6):402-409. 33. Sigal LH. Misconceptions about Lyme disease: confusions hiding behind ill-chosen terminology. Ann Intern Med. 2002;136(5):413-419. 34. Paddock CD, Greer PW, Ferebee TL, et al. Hid-

den mortality attributable to Rocky Mountain spotted fever: Immunohistochemical detection of fatal, serologically unconfirmed disease. J Infect Dis. 1999;179(6):1469-1476. 35. De Martino SJ, Carlyon JA, Fikrig E. Coinfection with Borrelia burgdorferi and the agent of human granulocytic ehrlichiosis. N Engl J Med. 2001; 345(2):150-151. 36. Warshafsky S, Nowakowski J, Nadelman RB, et al. Efficacy of antibiotic prophylaxis for prevention of Lyme disease. J Gen Intern Med. 1996;11(6):329333. 37. Nadelman RB, Nowakowski J, Fish D, et al; Tick Bite Study Group. Prophylaxis with singledose doxycycline for the prevention of Lyme disease after an Ixodes scapularis tick bite. N Engl J Med. 2001;345(2):79-84. 38. Chapman AS, Bakken JS, Folk SM, et al; Tickborne Rickettsial Diseases Working Group, CDC. Diagnosis and management of tickborne rickettsial diseases: Rocky Mountain spotted fever, ehrlichioses, and anaplasmosis—United States: a practical guide for physicians and other healthcare and public health professionals. MMWR Recomm Rep. 2006;55(RR-4):1-27. 39. Holman RC, Paddock CD, Curns AT, et al. Analysis of risk factors for fatal Rocky Mountain spotted fever: evidence for superiority of tetra-


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cyclines for therapy. J Infect Dis. 2001;184(11): 1437-1444. 40. Hamburg BJ, Storch GA, Micek ST, et al. The importance of early treatment with doxycycline in human ehrlichiosis. Medicine (Baltimore). 2008;87(2):53-60. 41. Krause PJ, Corrow CL, Bakken JS. Successful treatment of human granulocytic ehrlichiosis in children using rifampin. Pediatrics. 2003;112(3 pt 1):e252-e253. 42. Klein MB, Nelson CM, Goodman JL. Antibiotic susceptibility of the newly cultivated agent of human granulocytic ehrlichiosis: promising activity of quinolones and rifamycins. Antimicrob Agents Chemother. 1997;41(1):76-79. 43. National Institute for Occupational Safety and Health (NIOSH). NIOSH safety and health topic: tick-borne diseases (2008). www.cdc.gov/ niosh/topics/tick-borne. Accessed March 27, 2009. 44. Vázquez M, Muehlenbein C, Martter M, et al. Effectiveness of personal protective measures to prevent Lyme disease. Emerg Infect Dis. 2008;14(2):210-216. 45. Katz TM, Miller JH, Hebert AA. Insect repellents: historical perspectives and new developments. J Am Acad Dermatol. 2008;58(5):865871.