Atypical cause of forearm skin ulceration in a leukaemic child: mucormycosis. A case report

Primary cutaneous mucormycosis is an uncommon, deep and aggressive fungal infection occurring mainly in immunosuppressed or diabetic patients. Rapid diagnosis and therapy are necessary to prevent a fatal outcome. An eight-year-old leukaemic child presented with a dark necrotic ulcer on the volar-ulnar aspect of the left forehand. The lesion had developed over seven days, beginning as a vasculo-haemorrhagic erythematous plaque. There was no known history of trauma to the area, but skin necrosis from external compression caused by an intravenous line could not be completely ruled out. The lesion rapidly progressed to a 5 x 8 cm painful necrotic ulcer with an erythematous border. Treatment with ichthyol dressing and intra-venous antibiotherapy failed to improve the condition. Wide debridement was performed and specimens were sent for microbiology and pathology examinations. Microscopic examination demonstrated broad, irregularly walled, non-septate fungal hyphae that were consistent with Mucor. Amphotericin B was administrated intravenously (1 mg/kg/day) and hydrogel and hydrophile adhesive polyurethane foam dressings were applied. After 12 days, the soft tissue defect was covered with a split-thickness skin graft, harvested from the lateral aspect of the thigh. Diagnosis of this infection is based on complete histopathological and microbiological studies. Awareness, and a high index of suspicion are required because of the potential fulminant and fatal course.