Eumycetoma — DTM&H MCQ

Correct answer: B — Eumycetoma

The correct answer is B, Eumycetoma. The triad of painless, slowly progressive foot swelling, multiple discharging sinuses with grains, and radiological bone involvement over several years is the classic clinical picture of mycetoma, and black grains specifically point to a fungal (eu) rather than bacterial (actino) cause. Madurella mycetomatis is the dominant black-grain organism in the Sudan mycetoma belt, where farmers acquire infection through traumatic inoculation of soil organisms into the foot. The chronic granulomatous, tissue-destructive process explains why bone is eventually involved, and this indolent five-year course with grain discharge is inconsistent with any acute or superficial skin condition. Why the other options are wrong: A. Cellulitis due to Streptococcus pyogenes: this is an acute, painful, rapidly spreading soft tissue infection with erythema and systemic upset, not a five-year indolent process with sinus tracts and grains. C. Tungiasis: caused by the burrowing sand flea Tunga penetrans, producing a painful papule with a central black dot (the flea) typically on toes, not deep sinuses discharging grains or bone destruction. E. Acute gout: presents as a sudden, exquisitely painful, hot, swollen joint (classically first MTP), not a painless mass evolving over years with discharging sinuses. D. Scabies crustosa: is a hyperinfestation with mites causing widespread crusted, itchy plaques, not a localized swelling with sinus tracts, grains, or osteolysis. Key point: painless, chronic foot swelling with sinuses discharging black grains and bony involvement in an endemic farmer is eumycetoma until proven otherwise, and grain colour (black) points to a fungal rather than actinomycete aetiology.

Reference: WHO Target Product Profile for mycetoma diagnostics (2022): black grain eumycetoma is caused by fungi such as Madurella mycetomatis, endemic to Sudan, presenting with painless swelling, sinuses and bone involvement. https://www.who.int/publications/i/item/9789240047075