skip to main content

Lyme disease erythema migrans — MCCQE Part 1 MCQ

Instant feedback + full explanation. One question, done properly.

EasyFeverLyme disease erythema migransMCCQE Part 1

A 34-year-old hiker from Nova Scotia has fever, malaise and an expanding annular rash with central clearing after a tick bite. Which of the following is the most appropriate next step?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: C — Treat clinically for early Lyme disease without waiting for serology

Treat clinically for early Lyme disease without waiting for serology is the single best answer because the age, timing, examination findings and investigations in the vignette fit Lyme disease erythema migrans better than the alternatives. The most tempting distractor is less appropriate because it either treats a neighbouring presentation, delays a time-critical intervention, or ignores a key discriminator in the stem. The remaining options are suboptimal because they would miss the diagnosis, use an investigation or treatment in the wrong sequence, or fail to address safety and follow-up. Canadian practice should be anchored to PHAC Lyme disease guidance, with attention to acuity, safety-netting and local provincial pathways.

Reference: PHAC Lyme disease guidance