Tick Borne Illness
Lyme Disease
Pt with h/o spending time in grassy and heavily wooded areas presents with a non-tender erythematous rash with central clearing . Reports an episode of fatigue, headache, myalgia, and arthralgia following a tick bite that occured approximately two weeks. Denies any recent rhinorrhea, cough, or diarrhea [PE] on exam.
Labs
Imaging
Treatment
Administer prophylactic doxycycline 200 mg (4 mg/kg for pediatric ≥ 8+ years old) to non-pregnant patients only if ALL of the following criteria are met:
Attached deer tick in a region with ≥ 20 percent B. burgdorferi prevalence (New England, Wisconsin, Minnesota)
Tick attached for ≥ 36 hours (i.e. engorged)
Prophylaxis is started within 72 hours of tick removal
Erythema migrans: Doxycycline 100 mg BID for 14 days
Cardiac complication, and/or neurologic involvement: Doxycycline 100 mg BID for 21 days
Monoarticular arthritis: Doxycycline 100 mg BID for 28 days
Pt advised that cardiac involvement, monoarticular arthritis, and/or facial palsy may develop if Lyme disease is not appropriately treated
Pt counseled that non-specific symptoms such as fatigue, headache, and arthralgias may persist for 6 months to one year after treatment, however, there is no evidence that these symptoms are dangerous, represent ongoing infection, or can be improved with ongoing antibiotic treatment
Pt advised to wear protective clothing and apply insect repellent when spending time outdoors to prevent re-infection
Notes
Viral symptoms such as rhinorrhea, cough, and/or diarrhea suggest an alternate etiology
Symptom onset
Erythema migrans: 14 days after infection
Cardiac complications, monoarticular arthritis, and neurologic involvement: 28 days after infection
Lyme arthritis most commonly affects the knee