Histopathology guides targeted therapy for cutaneous leishmaniasis in French Guiana

A study of 268 American cutaneous leishmaniasis patients in French Guiana found that papular lesions, more than five lesions, and lower limb involvement were significantly associated with poorer treatment response, suggesting histopathology could guide targeted therapies. Researchers analyzed clinical and histological data from 245 confirmed cases between 2016 and 2024. The papulo-nodular form showed an anergic histological pattern and worse treatment outcomes, while a bacterial-infection-like form displayed neutrophilic folliculitis. Negative parasite loads correlated with large lesions, gold mining, and immunosuppression. Histopathology demonstrated 82% sensitivity and corrected diagnoses for 21 patients with negative parasitological tests. The authors propose that histopathology could guide targeted treatments, such as increased antiparasitic drug doses for papulo-nodular forms or neutrophil inhibitors for bacterial-like forms.