Acrodermatitis Chronica Atrophicans
ACA is a European form of borreliosis, caused by B. afzelii and B. garinii. It is transmitted by the Ixodes ricinus tick, and causes a morphea-like eruption. How do we treat it? One point. It differs from Erythema Chronicum Migrans by its lack of a raised, borrelia-infested erythematous border and by its scar-like appearance. Had I been confronted by this picture, without any history, I would have said morphea.
European borreliosis is much less likely to have multiple lesions, versus US borreliosis, and arthritis i s common as a sequela in the US, unusual in Europe. Also associated with B afzelii and garinii are lymphocytoma cutis, atrophoderma of Pasini and Pierini, and lichen sclerosus et atrophicus.