Acrodermatitis chronica atrophicans is a delayed manifestation of Lyme disease caused by a Borrelia burgdorferi subspecies, B. afzelii. Although rheumatic manifestations are rare, they can result in deformities of the fingers and toes if they are not treated promptly.
We report four cases of acrodermatitis chronica atrophicans seen over a 15-year period.
Two patients had a noninflammatory unilateral knee effusion and one had swelling of the dorsum of one hand. Antimicrobial therapy was followed by a full recovery in the three patients who received an early diagnosis. The remaining patient, a 63-year-old woman, had swelling and dysesthesia in the fingers of both hands. She developed finger deformities over a period of two years. Although the swelling resolved under antimicrobial therapy, she had persistent reducible deformities of the fingers consistent with Jaccoud's arthropathy.
The diagnosis of acrodermatitis chronica atrophicans rests on a history of a tick bite, a suggestive skin biopsy histology and a positive Western blot for B. afzelii. A positive response to antimicrobial therapy is also required. Acrodermatitis chronica atrophicans, a common condition in central and northern Europe, can cause joint manifestations and persistent finger deformities in the absence of early treatment.