The Clinical Features of Lichenoid Drug Eruption and the Histopathologic Differentiation Between Lichenoid Drug Eruption and Lichen Planus

Eom, Sang Cheul; Chae, Young Soo; Suh, Kee Suck; Kim, Sang Tae

Abstract

BACKGROUND: Lichen planus(LP) & lichenoid drug eruption(LDE) are similar in clinical manifestations and may pose difficulty in differentiation.
OBJECTIVE
& METHOD: We observed the clinical feature of 9 LDE patients and campared the histopathologic findings of LDE(11 specimens in 9 pateints) and LP(11 specimens in 11 patients).
RESULTS
Age of onset was predominant in old age, ranging from 49 to 71 years old. Causative drugs could be proved in seven patients and were ethanb atol in two cases, and thyroigen, pentazocin, furosemide, captopril and 5 fluorouracil in each of 5 cases. In the other two cases, either of INH, RIF or EMB was suspected as a causitire agent. Blood eosinophilia was present in 5 of the 6 exmmined patients. Comparative histolgjc features of LDE and I.P were as follows. (No. of specimen LDE/LP). parakeratosis (81), focal epidermal atrophy (8/0), focal loss of granular layer (9/0), colloid bodies in the gram laor horny layer (7/2), many necrotic keratinocytes (1/0), focal vacuolar alteration in the basal layer (5/0), extravasated RBC in the epidermis or derrnis (2/0), superficial and deep pervacular infiltrate (11/2), an infiltrate around the sweat glands(2/1), an infiltrate of eosinohils(11/0), an infiltrate of plasma celis(4/1).
CONCLUSION
LDE eouJd be differentiated from LP by cruhistory, cutaneous manifestations, blood eosinophilia and histopathologic findings. Histoetologic findings that were indicative of LDE were focal parakeratosis, colloid bodies in the gr nular or horney layer, focal epidermal atrophy, eosinophils and plasma cells in the cellula: ir filtrate and an infiltrate around deep vessels.