Skin manifestations of lyme borreliosis: diagnosis and management.

Lyme borreliosis is a multisystem infectious disease caused by tick-transmitted spirochetes of the Borrelia burgdorferi sensu lato complex. The three characteristic cutaneous manifestations are erythema migrans, borrelial lymphocytoma, and acrodermatitis chronica atrophicans. Erythema migrans occurs in acute Lyme borreliosis, lymphocytoma is a subacute lesion, and acrodermatitis is the typical manifestation of late Lyme borreliosis. Clinical appearances of erythema migrans and lymphocytoma (when located on the ear or breast) are characteristic, whereas acrodermatitis is often confused with vascular conditions. The diagnosis of erythema migrans is made clinically. Serologic analyses often yield false-negative results and are not required for the diagnosis. However, serologic proof of the diagnosis in lymphocytoma (approximately 90% positive) and acrodermatitis (100% positive) is mandatory. Histopathologic examination often adds substantial information in patients with skin manifestations of Lyme borreliosis and is recommended in clinically (and serologically) undecided cases of erythema migrans or lymphocytoma and is obligatory in acrodermatitis. Polymerase chain reaction for Borrelia-specific DNA (rather than culture of the spirochete) and immunohistochemical investigations (lymphocytoma) are sometimes necessary adjuncts for the diagnosis. Antibacterial treatment is necessary in all patients to eliminate the spirochete, cure current disease, and prevent late sequelae. Oral doxycycline, also effective against coinfection with Anaplasma phagocytophilum, is the mainstay of therapy of cutaneous manifestations of Lyme borreliosis. Other first-line antibacterials are amoxicillin and cefuroxime axetil. Erythema migrans is treated for 2 weeks, lymphocytoma for 3-4 weeks, and acrodermatitis for at least 4 weeks.