What is the hallmark early localized manifestation of Lyme disease?

• A. Erythema migrans
• B. Facial palsy
• C. AV heart block
• D. Arthralgia

Answer: (A)

In the early localized phase of Lyme disease, the defining sign is an expanding rash at the site of the tick bite, called erythema migrans. This lesion often appears within days to weeks after exposure and can grow to several centimeters, frequently with central clearing that gives a bull’s-eye appearance. The rash is typically not painful, though it may itch, and people may also feel fever, fatigue, malaise, headache, or muscle aches. This rash is clinically diagnostic when present, and antibody tests may still be negative early on. As the disease progresses, other problems like facial nerve palsy, heart block, or migratory joint pains appear in later stages, but the hallmark of the early localized phase is erythema migrans.