[Dermatological aspects of Lyme borreliosis]

Lyme borreliosis is a tick-borne zoonosis due to bacterial infection by Borrelia (B.) burgdorferi sensu lato The disease presents differently in Europe or North America and may be called European borreliosis when acquired in Europe. Lyme borreliosis evolves in 3 stages. The main manifestations include cutaneous, neurological, and joint involvement. Erythema migrans (EM) is the most specific and most frequent finding in patients with Lyme borreliosis. It is the hallmark of early-localized borreliosis. EM is a slowly expanding red macula that occurs in about 60-80% of patients contracting Lyme borreliosis. Central clearing of the red patch can occur. It appears at the site of the tick bite, 7 to 20 days after the bite. Borrelial lymphocytoma (BL) occur rarely in patients with the early-disseminated stage of the disease. BL is a red or brown nodule or plaque located on the nipple, the earlobe, the scrotum, or the face. It should not be confused with cutaneous B-cell lymphoma. Acrodermatitis chronica atrophicans (ACA) is the cutaneous manifestation of late borreliosis. It starts as a violaceous patch, usually located on the extensor surface of a limb. Periarticular nodules and cords can also be present. Without treatment, it will evolve over weeks or months to the typical atrophic stage with extensive dermo-epidermal atrophy and visibility of superficial veins. Only these 3 manifestations are clearly related to an infection with B. burgdorferi. The relationship between infection with B. burgdorferi and other dermatoses, especially morphea, lichen sclerosus, and interstitial granulomatous dermatitis is still debated.