The 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.

We sought to reassess the clinicopathological spectrum of ACA in a series of thoroughly documented cases.

Patients 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.

Twenty 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.

The small number of patients was a limitation.

Genuine 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.