De NovoHistoid Leprosy in an Elderly: A Case Report and Review of the Literature

Abstract

Histoid leprosy, an uncommon variant of lepromatous leprosy, develops usually as relapse in lepromatous patients who are on dapsone monotherapy, but uncommonly arises de novo. This rare form of the disease, with unique clinical and histopathological features, may pose a diagnostic challenge even to astute clinicians. We report the case that occurred de novo in an elderly who presented with small to large lesions all over the body. A fresh focus on histoid leprosy is the primary objective of this paper, especially in the context of the postglobal leprosy elimination era.

de novo Histoid leprosy: an expatriate case recently diagnosed in Johannesburg

“…These cases act as reservoirs of leprosy and spread the disease even after a very good control program. Additionally, the prevalence of de novo cases is increasing in the era of leprosy elimination, which is also a point of concern for leprologist to research for a genetic mutation in the bacilli causing drug resistance 9 .…”

Histoid Leprosy –A Case Report

“…In severe cases mucosa and genitalia may also be involved. The sites usually spared are the palms and soles [2]. An excoriated lesion found in our case was due to itching which could be due to increased proliferation of mast cells and their degranulation in the histoid nodule [6].…”

“…Bacteriologically, bacilli are longer than the normal, are uniform in length, more often solid with tapering ends and are arranged in parallel bundles along the long axis of the histiocytes (histoid habitus) without globus formation. Histopathologically, fusiform histiocytes are seen arranged in a whorled, criss-cross, or storiform pattern [2,3]. It can occur as relapse following dapsone monotherapy, incomplete therapy, resistance to antileprosy drugs, following multidrug therapy (MDT) and may in rare occasion arise de novo [4] but the exact etiopathogenesis is not clarified yet [5].…”