[Histoid leprosy in Morocco: retrospective study of 18 cases].

Introduction: Histoid leprosy is a special and rare anatomoclinical form of multibacillary leprosy. Most of the few large series describing this entity In literature have been reported from India. The purpose of this study was to analyze the epidemiological, clinical and therapeutic characteristics of patients with histoid leprosy in Morocco.

Material and methods: This retrospective study was conducted at the National Centre of Leprology (CNL) in Casablanca from January 1991 to December 2006. Only histologially confirmed cases of histoid leprosy were included. Epidemiological, clinical, histological and therapeutic characteristics were compiled from records and analyzed using EPI-Info version 6.

Results: Confirmed histoid leprosy accounted for 18 of the new cases of leprosy recorded at CNL recorded during the 16-year study period. There were 13 men and 5 women with a mean age of 35.2 years. Family exposure was noted in 9 patients (50%) including two who had more than two relatives with leprosy. Nodules/subcutaneous nodules were the most common morphological pattern (88.8%). Neurological involvement was found in 10 patients. Seven patients had grade 1 deformities. Slit skin smears from histoid lesions revealed abundant bacilli with a high bacteriological index ranging from 3 + to 5 + according to the Ridley index. All patients received antibiotic treatment according to the Moroccan protocol. Outcome was favorable in all patients. Six patients (33.3%) developed erythema nodosum leprosum during the course of disease. With a average follow-up of 9 years, no recurrence has been observed.

Discussion: Because of its multibacillary character and despite its rarity, histoid leprosy poses a challenge to the leprosy eradication in Morocco. Like other forms of multibacillary leprosy, histoid leprosy requires early detection and prompt multidrug therapy. These requirments should be made a priority in the national program against leprosy.