Descriptive study of sweat dermatitis: A rare dermatoses not so rare in tropics

Sweat dermatitis is an irritant inflammatory dermatosis commonly encountered in tropics during summers. Profuse sweating triggered by high heat index, friction, clothing, outdoor activities, military training, overcrowding, prolonged working in ill-ventilated places, etc., are responsible or this dermatitis. Aim was to study the clinical, dermoscopic, vapometric, histopathological, and immunohistochemistry (IHC) findings in sweat dermatitis.

Twenty-five patients of sweat dermatitis attending out-patient department (OPD) of tertiary care hospital, were recruited over a period of three months (June to August 2022). A detailed history was followed by dermatological examination, dermoscopy, vapometry, histopathology, and IHC studies.

Twenty-five patients were included in the study. There was male preponderance with male: female ratio of 2.1:1. The mean age of patients was 30.36 years. Dermatological examination in all patients revealed brownish "parchment"-like, shiny "crinkled cellophane paper"-like patches over the entire upper back and shoulder region with areas of exfoliation. Dermoscopy revealed increased skin markings, deep brown pigmentary changes with superimposed whitish scales with islands of eroded skin, and prominent eccrine duct openings. Vapometric analysis revealed increased transepidermal water loss (TEWL) in the affected area in 88% of patients. Histopathological examination showed features of spongiotic dermatitis. IHC with CK7 (cytoplasmic) highlighted the normal eccrine coils.

Sweat dermatitis is common seasonal dermatoses in tropics, but it remains undiagnosed due to lack of awareness. This study aims to sensitize medical doctors and dermatologists about sweat dermatitis and prevention strategies that can be helpful in mitigating it. The study also discusses the role of investigative modalities, such as dermoscopy, vapometry, histopathology, and IHC, in sweat dermatitis.