Intertrigo (Skin Fold Dermatitis)

Intertrigo is an inflammatory eruption of opposed skin surfaces (inframammary, axillary, abdominal pannus, inguinal, gluteal, interdigital, and neck folds) caused by friction, heat, moisture, and lack of air circulation. Maceration disrupts the stratum corneum and allows colonization or infection by Candida albicans, dermatophytes, Staphylococcus aureus, beta-hemolytic streptococci, and Pseudomonas aeruginosa. Erythrasma (Corynebacterium minutissimum) presents as a red-brown patch with coral-red Wood lamp fluorescence.

Clinical features are well-demarcated erythema, maceration, fissuring, and burning or itching; satellite pustules suggest Candida, weeping crusts suggest Staphylococcus impetiginization, sharply marginated annular plaques suggest dermatophyte, and pruritic vesicles with overlying eczematization may indicate inverse psoriasis or seborrheic dermatitis. Diagnosis combines clinical recognition, KOH preparation, bacterial swab, and Wood lamp examination.

Management focuses on drying and separating skin folds with absorbent powders or gauze, weight reduction, treatment of hyperhidrosis, and breathable cotton clothing. Topical low-potency steroid (hydrocortisone 1-2.5%) for inflammation, topical azole (clotrimazole, miconazole) or nystatin for Candida, mupirocin or topical clindamycin for staphylococcal involvement, and oral antibiotics for cellulitis. Erythrasma responds to topical clindamycin, fusidic acid, or oral erythromycin. Recurrence prevention includes moisture management and treatment of underlying diabetes or obesity.