Zosteriform lichen planus: a new variant of a common disorder

Abstract

Background Lichen planus (LP) is generally easily recognizable but sometimes it comes in disguise. It has been reported to occur in the scars of previous herpes zoster lesions. Zosteriform pattern in LP, without evidence of herpes zoster, is an extremely rare occurrence. We describe a series of nine patients seen with this peculiar pattern.Materials and methods Nine patients of varied ages presenting during Jan, 2002 to Dec, 2003, with grouped lichenoid lesions on various regions of the body. There was no previous or concomitant history of herpes zoster on the involved site or elsewhere on the body. Lesions were clinically assessed and laboratory investigations including blood counts, blood sugar, serum liver function tests, serology for hepatitis B and C, serum urea and creatinine were carried out. Skin biopsies were also performed for histopathological studies in all cases.Results Most patients were young to middle aged males. No associated systemic clinical illness was seen in any patient. Skin lesions were suggestive of LP. Laboratory investigations were within normal limits in all patients except one, who was positive for hepatitis C. Skin biopsies revealed classical changes of lichen planus in most cases.Discussion Linear lesions following lines of Blaschko have not been so uncommon, but zonal or zosteriform distribution of LP lesions without koebnerization is a very rare occurrence. Exact etiology of this unusual pattern could not be ascertained. The possible cause could be an unknown drug, food or a form of blaschkitis.Conclusion. Zosteriform LP is an emerging new variant, which should be looked for in clinical practice.