Hx living in area endemic w/lyme→ Northeast, WI/MN, Northern Calif
Occurs secondary to tick bite x 24-48h
Walking in an endemic area wearing shorts, t-shirts and not using tick repellent (e.g. DEET containing products)

Early localized disease (within 3-30 d of bite): erythema migrans in ~85%, typically occurs at bite site w/in days to 1m
Early disseminated disease (within 3-30d): fever, chills, myalgias, arthralgias, adenopathy, fatigue, brief mono-articular arthritis, bells palsy (or other CN dysfunction), headache from CNS involvement (aseptic meningitis), peripheral neuropathy (pain, sensory loss, weakness), carditis→heart block (SOB, syncope, lightheaded/dizzy, CP, palpitations)
Late disseminated disease (weeks-to-months-to-years after infection): occurs in < 10% of infections; joint inflammation and pain, large joints (e.g. knee), can wax/wane; peripheral neuropathy; encephalomyelitis (memory deficits); usually no systemic symptoms
Can co-infect w/organisms causing babesiosis and anaplasmosis

Early local: e migrans→ red papule to macule, often uniformly red but can have central clearing or necrosis; can be asx, painful or puritic; enlarges and can last 1m if untreated
Early disseminated: fever, peripheral CN 7 palsy or other cranial nerve dysfunction, bradycardia from heart block, diminished sensation and weakness from peripheral neuropathy (multiple spinal nerve roots), adenopathy
Late disseminated: large joint pain (e.g. knee), swelling, effusion

Lyme (Borrelia Burgdorferi)