A 35-year-old farmer from Bihar presents with a chronic painless swelling on his foot for 3 years with multiple draining sinuses discharging black granules. Histopathology shows the Splendore-Hoeppli phenomenon. The most likely diagnosis and its causative organism are:
- A Actinomycetoma (Actinomadura madurae) — antibacterial therapy
- B Chromomycosis (Fonsecaea pedrosoi) — itraconazole
- C Sporotrichosis (Sporothrix schenckii) — potassium iodide or itraconazole
- D Eumycetoma caused by Madurella mycetomatis — itraconazole or voriconazole ± surgery ✓
Explanation
Madura foot (mycetoma) with black granules is characterised by the Madura triad: painless swelling, draining sinuses, and granule discharge. Black granules indicate eumycetoma (fungal) — Madurella mycetomatis is the most common cause of eumycetoma in India and produces black/dark granules. White/yellow granules suggest Actinomycetoma (bacterial — Actinomadura madurae or Nocardia). Histopathology shows eosinophilic material surrounding granules — the Splendore-Hoeppli phenomenon (deposited immunoglobulin and complement around the organism). Eumycetoma is treated with itraconazole or voriconazole for years; surgery is added when medical therapy fails. Differentiation between actino- and eumycetoma is critical because treatment differs (antibacterials vs antifungals).
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.