A Lesson on Lyme
by Leonard H. Sigal, MD
Associate Professor of Medicine and Chief, Division of Rheumatology at UMDNJ-Robert Wood Johnson Medical School and Director of the Lyme Disease Center
Lyme disease was first identified about 20 years ago in patients from three small towns along the east bank of the Connecticut River. Since that time we have learned a great deal about: the clinical manifestation and treatment of the infection; the organism, Borrelia burgdorferi itself, and how it evades and modifies the human immune response to cause disease; the tick vectors; and the ecology of the animal hosts of the organism and vectors.
We've developed and improved upon diagnostic tests, devised different strategies for development of a vaccine - two vaccines are being tested in clinical trials - and have held several international meetings to discuss Lyme disease. There have been a host of scientific and lay publications on the subject, large numbers of support group meetings and lectures, and yet there is still confusion about the disease.
Part of this is due to the fact that early on there were few attempts at organized lay and medical education, and a great deal of misinformation and misinterpretation of facts flowed into the vacuum created by that lack of education. Lyme disease was incorrectly called "The Great Imitator" because of its apparent ability to mimic other diseases.
Medical researchers stated that diagnostic tests were not perfect and conceded that antibiotic therapy was not universally effective. Unfortunately, the result of these acknowledgements is the all-too-common finding that some local "Lyme disease experts" diagnose nearly every clinical problem they see in their practices as Lyme disease, ignore negative serologic testing results or misinterpret marginal or false-positive results, and treat ill-defined syndromes for months or years with dangerous antibiotic regimens.
The clinical manifestations of Lyme disease are now well described. It is not, and has never been, a mimic of all syndromes and diseases. The serologic and molecular biologic diagnostic tests are as accurate as most such tests for infectious disease, but they should be used only with a full understanding of their limitations. Antibiotic therapy of standard duration and dosage is appropriate for the clinical manifestations of the infection and is effective in the treatment and cure of Lyme disease in the vast majority of cases.
Lyme disease remains the most common vector-borne infectious disease in the U.S. However, two new tick-borne diseases have gained public attention as well: Babesiosis (caused by Babesia microti) and the human granulocytic Ehrlichia. Both are spread by deer ticks. The clinical syndromes caused by Babesia and Ehrlichia are different from Lyme disease, although the ticks can carry B. burgdorferi at the same time as either of these other pathogens. Thus patients can be co-infected with B. burgdorferi and either of these other organisms by the same tick bite.
At the December 1994 National Clinical Conference on Lyme Disease, 10 experts presented the clinical state of the art on the infection. Panel discussions followed, allowing for interchange with clinicians. The conference was sponsored by the UMDNJ Center for Continuing Education and the American Lyme Disease Foundation, Inc.; it was underwritten by Connaught Laboratories, Inc.
The post-conference test (which follows) that was developed for attending physicians who were getting CME credit covers what should now be basic knowledge for anyone diagnosing and treating Lyme disease.
TEST QUESTIONS:
NATIONAL CLINICAL CONFERENCE ON LYME DISEASE
For each question, circle the one best answer.
1. Currently, Lyme disease is
- A. Overdiagnosed
- B. Underdiagnosed
2. If Lyme disease is suspected, a second serum sample should be tested after how much time?
- A. 24 hours
- B. 1 to 2 weeks
- C. 4 to 6 weeks
- D. 8 weeks
3. Which outer surface protein is a particularly good marker of early-stage Lyme disease?
- A. OspA
- B. OspB
- C. OspC
4. Which outer surface protein may have a role in the immuno-pathogenesis of therapy-resistant Lyme arthritis?
- A. OspA
- B. OspB
- C. OspC
5. Borrelia burgdorferi can be cultured from spinal fluid in about what percentage of suspected Lyme disease cases?
- A. 10%
- B. 30%
- C. 50%
- D. 80%
6. Commercially available serologic tests for Lyme disease have poor specificity, sensitivity, and reproducibility.
- A. True
- B. False
7. ELISA may yield false-positive results for Lyme disease in patients with which of the following diseases?
- A. Syphilis
- B. Systemic lupus erythematosus
- C. Infectious mononucleosis
- D. All the above
8. Which characteristic is atypical for erythema migrans?
- A. Association with systemic symptoms
- B. Minimal pruritus or tenderness
- C. Occurrence in February
- D. Location of rash in the axilla
9. Which of the following would not support the diagnosis of erythema migrans?
- A. The lesion has expanded from 3 cm to 12 cm over several days
- B. A 7-cm lesion has been present, without change,
- for the previous 4 months
- C. The patient has a fever of 39° C
- D. The lesion has a small area of scale only in the center
10. What is the median time after a tick bite before erythema migrans develops?
- A. 1 to 3 days
- B. 4 to 6 days
- C. 7 to 10 days
- D. 14 to 21 days
11. Which statement about erythema migans is not true?
- A. Less than 1/3 of patients recall a prior tick bite at the site of the rash
- B. Erythema migrans is more likely to follow a nymphal Ixodes scapularis tick bite than one from another stage of this tick
- C. Virtually all cases of erythema migrans demonstrate central clearing
- D. Erythema migrans lesions resolve spontaneously (i.e., without antibiotic treatment)
12. The CDC surveillance definition of Lyme disease requires erythema migrans lesions to be at least how wide in diameter?
- A. 3 cm
- B. 4 cm
- C. 5 cm
- D. 6 cm
13. Most patients with erythema migrans have associated systemic complaints.
- A. True
- B. False
14. Which are the first-choice oral antibiotics in adults for early Lyme disease characterized by erythema migrans?
- A. Amoxicillin and doxycycline
- B. Azithromycin and clarithromycin
- C. Erythromycin and cefuroxime axetil
- D. Penicillin and tetracycline
15. Which of the following is not a common complaint of early Lyme disease?
- A. Arthralgia and myalgia
- B. Cough and coryza
- C. Fever and chills
- D. Headache and stiff neck
16. The incidence of Lyme carditis appears to be higher in Europe than in the United States.
- A. True
- B. False
17. Where are chronic cutaneous manifestations of Lyme disease more frequently reported?
- A. Europe
- B. United States
18. Which is the most likely explanation for differences in clinical expression of Lyme disease between Europe and the United States?
- A. Different patient populations
- B. Differences in Borrelia burgdorferi
- C. Observer bias
19. In what way does Lyme carditis differ from most other manifestations of Lyme disease?
- A. Antibiotics do not cure most cases
- B. It usually leads to chronic complications
- C. There is a male predominance
- D. All the above
20. Where does heart block in Lyme carditis usually occur?
- A. Above the bundle of His
- B. Within the bundle of His
21. Palsy of which cranial nerve is often an early clinical manifestation of Lyme neuroborreliosis?
- A. IV
- B. V
- C. VI
- D. VII
22. What is the antibiotic of choice for the management of Lyme meningitis?
- A. Oral amoxicillin
- B. IV cephalosporin or penicillin
- C. Oral doxycycline
- D. Any of the above
23. Long-term (>1 month) IV antibiotic therapy is appropriate in which patients?
- A. Those with definite Lyme meningitis
- B. Those with probable Lyme arthritis
- C. Those with possible Lyme neuroborreliosis
- D. None of the above
24. Lyme disease can affect which neurologic sites?
- A. Peripheral nerves
- B. The meningeal lining of the central nervous system
- C. The central nervous system parenchyma
- D. All the above
25. Which of the following is not common in early Lyme disease?
- A. Diffuse, nonspecific myalgia
- B. Muscle stiffness
- C. Myositis
26. The myositis that may be seen with Lyme disease is commonly
- A. Diffuse
- B. Localized
27. Which is the most common joint site for Lyme arthritis?
- A. Ankle
- B. Elbow
- C. Hip
- D. Knee
28. Fibromyalgia, which can be confused with Lyme arthritis, is characterized by all the following except
- A. Marked fatigue
- B. Severe headache
- C. Joint inflammation
- D. Diffuse musculoskeletal pain
29. Which is generally the drug of choice in the treatment of late Lyme disease?
- A. Amoxicillin
- B. Ceftriaxone
- C. Doxycycline
- D. Penicillin
30. Criteria that may be used to attribute ocular findings to Lyme disease include which of the following?
- A. Clinical findings of Lyme disease in other organs
- B. Occurrence in patients living or having traveled in endemic areas
- C. Lack of evidence of other diseases to explain the ocular findings
- D. All the above
31. What is the recommended therapy for persistent vitritis in Lyme disease?
- A. Extended antibiotics
- B. Topical steroids
- C. Vitreous tap
- D. All the above
32. Patients with which form of Lyme disease usually have the highest levels of IgG antibody to Borrelia burgdorferi?
- A. Dermatologic manifestations
- B. Lyme arthritis
- C. Neuroborreliosis
- D. Ocular manifestations
33. In which patient population was Lyme disease first identified?
- A. Infants
- B. Children
- C. Adults
- D. Elderly
34. Which is the most common presenting manifestation of Lyme disease in children?
- A. Arthritis
- B. Carditis
- C. Erythema migrans
- D. Meningitis
35. Children tend to have more long-term complications of Lyme disease than do adults.
- A. True
- B. False
36. Transmission of Lyme disease through breast-feeding has been documented.
- A. True
- B. False
37. In which states is Lyme disease not endemic?
- A. Massachusetts, Rhode Island, Connecticut
- B. New York, New Jersey
- C. South Carolina, Florida
- D. Wisconsin, Minnesota
38. Which stage of deer tick is responsible for nearly 90% of cases of Lyme disease?
- A. Egg
- B. Larva
- C. Nymph
- D. Adult
39. All of the following statements are true except?
- A. Complete removal of an attached tick is not necessary to prevent transmission of Borrelia burgdorferi
- B. The life cycle of the deer tick is 2 years
- C. The main source of Borrelia burgdorferi infection of ticks is the white-footed field mouse
- D. The main host of nymphal ticks is the white-tailed deer
40. What is the best time of year for insecticide treatment of tick-infested areas?
- A. Mid-March
- B. Mid-May
- C. Mid-July
- D. Mid-September
41. Deer exclosure by fencing can significantly reduce the risk of Lyme disease.
- A. True
- B. False
The best way to optimize the care of our patients and minimize misdiagnosis and mistreatment is for patients and physicians to learn the facts about Lyme disease.
The answers to the quiz are PRESS HERE. For copies of papers presented at the Lyme disease conference or to suggest topics or presenters for UMDNJ's Continuing Education programs, contact Paul Novembre by phone at 201-982-5309 or fax to 201-982-7128. The e-mail address is cce@umdnj.edu