Collagen depletion, not keloid formation, defines lobomycosis lesions: a paired skin analysis.

Lobomycosis is a chronic cutaneous infection caused by the uncultivable fungus Paracoccidioides lobogeorgii. Lesions are often described as keloid-like, but the organization of the dermal extracellular matrix remains poorly characterized. We analyzed paired lesional and non-lesional skin from five patients in the Brazilian Amazon using histology and immunohistochemistry. Picrosirius red staining revealed depletion and disorganization of type I collagen in lesional dermis. Immunohistochemistry showed modest differences in biglycan and decorin expression, with spatial redistribution of biglycan near fungal structures. Patients treated with itraconazole showed lesion stabilization. These findings indicate collagen loss rather than true keloid formation.