The evolution of clinicopathologic features in eruptive lichen planus: a case report and review of literature.

"Eruptive" or "exanthematous" lichen planus (LP) is a rare variant of lichen planus. Here we report a middle-aged woman with a 6-month history of episodic eruptive LP presenting as generalized, erythematous, flat-topped, round, polygonal, or umbilicated papules and hyperpigmented macules. The disease was under good control with continuous low-dose prednisolone over one year. We had the opportunity to correlate the clinical and pathologic findings based on histopathologic examination of three separate skin lesions that appeared to represent different stages of evolution. Recognition of these 3 chronological manifestations (polygonal papule in active inflammation, centrally umbilicated papule in involution, and hyperpigmented macule in resolution) can aid the diagnosis.