Fusarium Solani Causing Quasi-Invasive Infection of the Foot in an Immunocompetent Middle-Aged Man from South India
A 45-year-old male presented with asymptomatic subcutaneous swelling of left heel and right forefeet of 15 years duration with 2 ulcers over sole of right foot. Onset was insidious and spontaneous in nature. There was no history of trauma or prick by wooden splinter or thorn. Swelling was painless and gradually increased to the present size. Patient ignored the swelling, as it was not bothering. Recently, he developed 2 ulcers over right foot spontaneously. There was no history of discharge or grains from the ulcer. Examination revealed gross subcutaneous swelling of heel of left foot with few nodules with verrucous changes of overlying skin and few pinpoint pustules []. Other parts of left foot were normal. Front portion of right foot was grossly swollen and deformed with a 2 × 2 cm oval superficial ulcer with irregular borders, sloping edges, and pale granulation tissue at the floor was seen []. Blood investigations like complete blood counts, blood sugars, liver and renal function tests were within normal limits. X-ray of bilateral foot was done, which showed osteolytic lesions in right foot. Skin biopsy was sent to pathology and microbiology for evaluation. Histopathological evaluation showed hyperkeratosis, parakeratosis, and acanthosis of epidermis. Dermis showed infiltration by neutrophils and lymphocytes. Special stains for fungus were negative. KOH mount with additional parker ink of the biopsy sample showed thin, slender, branching, septate, hyaline filamentous fungi appearing blue []. Fusarium Solani was grown on Sabourauds dextrose agar at 28°C showing off-white, aerial, fluffy to floccose obverse with pale yellow, diffuse reverse pigmentation, and second biopsy sample was sent for confirmation. Culture of second biopsy sample also showed growth of Fusarium Solani [].\nMicroscopy of lactophenol cotton blue slide culture mount of Fusarium Solani revealed thin, slender, hyaline hyphae with septate, fusiform macroconidia, microconidia, and chlamydospores. Patient was started on itraconazole 100 mg twice-daily with regular follow-up. Patient showed good improvement after 2 months with healing of ulcers in the right foot and reduction in swelling in left foot.