Erythrasma is a Corynebacterium minutissimum infection of the skin affecting the moist flexures such as groin, axilla and under the breasts, It clinically resembles the rash of dermatophytes and can be differentiated by examining the skin under Wood's light. Corynebacterium gives off a characteristic coral pink fluorescence, as seen in the groin crease and inner thigh in the image above. A topical antibiotic such as 2% fusidic acid is effective for its treatment. Image via: https://stamfordskin.com/en/dermatology/erythrasma/