Expanding the clinicopathological spectrum of late cutaneous Lyme borreliosis (acrodermatitis chronica atrophicans [ACA]): A prospective study of 20 culture- and/or polymerase chain reaction (PCR)-documented cases

BackgroundThe diagnosis of acrodermatitis chronica atrophicans (ACA), the late cutaneous manifestation of Lyme borreliosis, can be challenging. Histologic changes in ACA have been described in a few studies from endemic countries, relying on cases documented by serology only.ObjectivesWe sought to reassess the clinicopathological spectrum of ACA in a series of thoroughly documented cases.MethodsPatients prospectively included in a national prospective study were selected on the basis of positive culture and/or polymerase chain reaction of a skin biopsy sample. The diagnosis of ACA was confirmed by reviewing the clinical and serologic data. Histopathological samples were carefully reviewed.ResultsTwenty patients were included. Unusual clinical features (ie, numerous small violaceous patches and equidistant small spinous papules with background faint erythema) were observed in 2 patients. Histopathological examination revealed a classic plasma cell–rich perivascular and interstitial pattern with telangiectases in 16 of 25 samples, whereas strikingly prominent granuloma annulare–like or lichenoid features were observed in 4 and 2 of 25 cases, respectively, and discrete nonspecific minor changes in 3 of 25 cases.LimitationsThe small number of patients was a limitation.ConclusionsGenuine culture- and/or polymerase chain reaction–proven ACA can rarely present as numerous violaceous patches or cluster of spinous papules clinically, and as a granuloma annulare–like or lichenoid dermatosis histologically.