Fungal density in Lobomycosis in French Guiana: proposal for a new clinico-histological and therapeutic classification

Abstract

Background

Lobomycosis is a rare cutaneous tropical neglected disease, caused by the fungal agent Lacazialoboi, recently renamed Paracoccidioides lobogeorgii. Our objectives were to present all cases of lobomycosis diagnosed in French Guiana, to offer a precise description of their histopathological features and to propose a new clinico-histological prognostic classification.

Methods

All cases of lobomycosis diagnosed in French Guiana between 1959 and 2022 were included. We looked for associations between the occurrence of relapses and the clinic-histological form.

Results

31 patients diagnosed with lobomycosis were included. An epidemiological shift was observed in the 2000s as Brazilian patients became the most important ethnic group. Gold mining, forestry and fishing/sailing were reported as professional exposures. New histological features such as inflammatory “rosettes” formations were described. We describe two clinic-histological patterns: a major form (high fungal density and/or multifocal lesions) and a minor form (low fungal density, unifocal lesions, association with less relapses).

Discussion

The changing epidemiology of lobomycosis in French Guiana is characterized by a shift towards Brazilian patients, mostly gold miners. Minor forms should be treated with surgery, major forms with a combination of surgery followed by Multiple drug therapy (MDT) or Posaconazole.