Actinomycetoma Due to Nocardia brasiliensis: Recognition in Primary Care

Mycetoma is a chronic, progressively destructive subcutaneous infection caused by aerobic filamentous bacteria (actinomycetoma) or true fungi (eumycetoma). It represents one of the most neglected tropical diseases, disproportionately affecting vulnerable populations in resource-limited rural settings. In Latin America, actinomycetoma predominates, most commonly caused by Nocardia brasiliensis. Delayed diagnosis is frequent due to its indolent course and limited awareness at the primary care level, often resulting in severe deformity, disability, or amputation. We report the case of a 43-year-old agricultural worker from rural Bolivia who presented with a two-year history of progressive, painless swelling of the right foot and ankle, associated with multiple draining sinus tracts extruding whitish grains. Based on the classic clinical triad and epidemiological context, mycetoma was suspected in the primary care setting. Direct microscopic examination supported actinomycetoma, and empirical antibiotic therapy was initiated. Culture later confirmed Nocardia brasiliensis. Histopathology demonstrated a basophilic grain surrounded by suppurative and granulomatous inflammation. This report underscores the critical role of primary care physicians in the early clinical recognition of mycetoma using basic diagnostic tools, particularly in endemic and underserved regions. Prompt identification and timely referral of actinomycetoma can substantially reduce morbidity, prevent irreversible tissue damage, and improve functional outcomes.