[Familial histoid leprosy]

Histoid leprosy is a very particular and rare anatomoclinical form of lepromatous leprosy. Familial cases are extremely rare. We report two new cases of histoid leprosy in a sister and brother born of a non-consanguineous marriage.

We report the case of a sister and brother, aged 21 and 25 years respectively, who were admitted to the National Leprology Centre for multibacillary leprosy. Questioning revealed the existence of family contact with an uncle and two maternal cousins, all of whom had histoid leprosy. On clinical examination, multiple erythematous papules and nodules were noted, some of which were umbilicated while others were ulcerated. Palpation also revealed subcutaneous nodules on the thighs and forearms. No neurological disorders were found in the two patients. Histopathological analysis of cutaneous biopsy samples of nodular lesions for the two patients showed dermal-hypodermic nodular infiltrates comprising spindle cells with a few macrophages. Ziehl-Neelsen staining showed numerous alcohol-acid resistant bacilli (BAAR) without globi. Both patients were placed on the multi-drug regimen recommended by the WHO for multibacillary leprosy. An extremely favourable therapeutic response was obtained after 3 months of treatment. The patients had presented no relapse of erythema nodosum leprosum after two years of follow-up.

Histoid leprosy is a clinical entity that must be clearly differentiated through its clinical and histopathological features, which distinguish it from polar lepromatous leprosy. There may be a genetic predisposition to this clinical leprosy form, but this requires confirmation by genetic studies.