Hyperkeratotic Warty Skin Lesion of Foot Caused by Fusarium oxysporum
A 50-year-old male, farmer by occupation, used to work barefoot in the fields, developed cracked heels. The lesion began in the form of small painless papules and slowly progressed to painful hyperkeratotic warty lesion over a period of 1 year. There was no discharge of pus or granules from the lesion.\nExamination of the skin lesion showed hyperkeratotic, verrucous skin lesions, firm to touch and surrounded by erythema []. No sinus or grains could be seen. No other lesion was seen at any other site in the body, ruling out disseminated infection. No lymphadenopathy was noted, and the physical examination was normal. A differential diagnosis of chromoblastomycosis, tuberculosis verrucosa cutis, sporotrichosis, and psoriasis were kept in mind, and the patient was investigated.\nSkin biopsy was taken from the lesion. Direct KOH mount of the lesion showed septate branching hyaline hyphae. Culture done on Sabourauds Dextrose Agar (SDA) with and without cycloheximide revealed whitish-grey cottony colonies after 5 days of incubation at 22°C. Lactophenol cotton blue mount from the colonies showed branched septate hyphae with large sickle-shaped macroconidia and single-celled microconidia, suggestive of Fusarium spp. On slide culture, the species was found to be Fusarium oxysporum []. On histopathology, hyperkeratosis with fungal hyphae were detected []. Ziehl Neelsen staining did not show any acid-fast bacilli. Blood culture of the patient for fungal pathogens was negative. X-ray foot of the patient did not reveal any bony invasion. The patient was not immunocompromised as suggested by a negative HIV status, normal neutrophil count and blood sugar levels, no evidence of any hematological malignancy.\nThe patient was put on oral itraconazole 400 mg/day therapy along with local debridement.