Subcutaneous mycoses in coastal Karnataka in south India

Subcutaneous mycoses are chronic, localized infections of the skin and subcutaneous tissue which occur following traumatic implantation of the etiological agent. The causative organisms are soil saprophytes of regional epidemiology with varying ability to adapt to the tissue environment and elicit disease.

This study was conducted to evaluate the various types of subcutaneous mycoses, including actinomycotic mycetomas, in south coastal Karnataka, India.

Between January 2005 and January 2013, a total of 25 patients were diagnosed with subcutaneous mycoses based on a detailed clinical history and presentation, histopathology, and culture of organisms.

Chromoblastomycosis was the infection most commonly seen (n = 16 patients, 64%), followed by mycetoma (n = 4, 16%), sporotrichosis (n = 4, 16%), and rhinoentomophthoromycosis (n = 1, 4%). The extremities were the most common site of involvement, with the lower limb being most affected (64%). Males were more commonly afflicted (64%) than females (36%). Most patients were agricultural workers, although preceding trauma was noted in only three patients. The majority of patients responded well to therapy and were disease-free on follow-up.

Subcutaneous mycoses are a rare group of disorders. Chromoblastomycosis is the most frequent subcutaneous fungal infection in south India. Morphologically, chromomoblastomycoses present as verrucous, ulcerative, nodular, or eczematous lesions. Clinical diagnosis is important as culture is often negative. The incidence of infection is higher among rubber tappers. It is important to clinically differentiate chromoblastomycosis from tuberculosis verrucosa cutis. Most of the subcutaneous mycoses respond well to treatment, with the exception of rhinoentomophthoromycosis, which is a rare form of deep mycosis with associated mutilation. Eumycetomas are not observed in this part of India.