Snapshot A 16-year-old boy presents to his primary care physician with fatigue, headache, and arthralgia. The doctor identifies a ring-shaped lesion on his lower back. Introduction Lyme Disease is caused by the spirochete Borrelia burgdorferi Transmitted by the Ixodes tick on white-tailed deer and white-footed mice tick must attach 36-48 hours in order to trasmit B. burgdorferi Most common vector-born disease in the USA Usually observed in the summer months in the Northeast, northern midwest, and California the disease occurs worldwide Disease usually presents in three distinct stages, characterized by symptoms below Presentation Symptoms prodrome symptoms include fever malaise photophobia erythema chronicum migrans 7-14 days after tick bite spreading circular red rash with central-clearing secondary disease symptoms appear weeks after bite and include weeks-months after tick bite cardiac symptoms myocarditis conduction abnormalities palsies (i.e. Bell's palsy) aseptic meningitis joint pain (migratory polyarthropathies) tertiary disease symptoms appears weeks to months after bite and include months-years after tick bite arthritis subacute encephalitis memory and mood changes Physical exam prodrome symptoms usually accompanied by identifiable rash identified in areas difficult for patient to see (i.e. lower back, postauricular) all other signs and symptoms identified as described Evaluation Diagnosis based primarily clinical and laboratory findings ELISA if positive, only denotes exposure not specific for active disease Western blot used to confirm positive or indeterminate ELISA Skin biopsy and/or tissue culture of migrating rash may help identify pathogen PCR may aid in identification of Borrelia burgdorferi DNA Differential Contact dermatitis, other tick-borne illness (Rocky Mountain Spotted Fever, etc), Treatment Medical management doxycycline indicated for treatment of early disease contraindicated in pregnant women and children <8yo side effects include photosensitivity - must caustion patients to avoid sun exposure amoxicillin: first line treatment for children < 8 yo high-dose penicillin or ceftriazone indicated for treatment of more advanced disease given for period of 2-4 weeks Macrolides (erythromycin, azithromycin) third line agent if doxycycline contraindicated and allergic to penicillin empiric therapy indicated for patients with characteristic rash, arthralgias, or a tick bite in endemic areas but without confirmed diagnosis Prognosis, Prevention, and Comlications Prognosis good to excellent if identified early and treated appropriately poor to fatal if left untreated Prevention take precautions in endemic areas (i.e. wear long clothes, apply DEET insect repellent) examine body for tick bites after potential exposures Complications unidentified/untreated disease can progress to meningitis/encephalitis and death