A young man sought medical attention after a motorcycle mishap that led to multiple leg abrasions. One such lesion expanded rapidly and became progressively painful. The patient was alarmed when the center of the lesion turned dark.
Key point: The black, hard center represents an eschar. This type of morphology is almost always caused by a virulent organism—bacterial or fungal. Because of the outdoor, traumatic onset, a fungal etiology was suspected. A biopsy showed non-septate hyphae within the dermis, and a culture grew Mucor species (a saprophytic soil fungus).
Treatment: Wide surgical debridement and intravenous administration of liposomal amphotericin-B were required to stop the spread of the destructive lesion and thereby save the leg.
Note: Similar cases have occurred, in both adults and children, following significant automobile accidents.