Candidal Intertrigo

Infection of skin folds by Candida species, most often C. albicans (also C. glabrata and C. parapsilosis in recurrent or antifungal exposed cases). It is the commonest infectious cause of intertrigo.

Warmth, moisture and maceration promote yeast overgrowth. Obesity, diabetes mellitus (poor glycaemic control, glycosuria with SGLT2 inhibitors), antibiotic or corticosteroid use, immunosuppression (HIV, chemotherapy), incontinence, occlusive dressings and hot humid climates are the key risk factors.

In infants, it complicates diaper dermatitis. In adults it involves the inframammary, axillary, inguinal and abdominal folds, and the web spaces of the hands and feet.

Recurrent or severe disease should prompt a search for diabetes and HIV.

• Bright red, moist, glazed, sharply demarcated patches in the fold, often with a fissure at the depth and a thin white or macerated rim.
• Satellite papules and pustules scatter beyond the main patch and are a defining sign.
• Itching, burning and soreness, often with odour.
• In the groin, involvement of the scrotum and penis (balanitis) or vulva (vulvitis) is common.
• Differential diagnosis: inverse psoriasis, tinea cruris (scaly raised margin, spares the scrotum), erythrasma, seborrhoeic dermatitis, contact dermatitis, hidradenitis suppurativa, Hailey-Hailey disease and extramammary Paget disease.
• Complications: bacterial superinfection, fissuring, chronic recurrence, and rarely invasive candidiasis in the immunocompromised.

• Clinical. Potassium hydroxide preparation of scrapings shows budding yeast and pseudohyphae. Culture identifies the species and guides treatment in recurrent disease.
• Check HbA1c or fasting glucose, and perform an HIV test in recurrent or severe disease. Review medicines (SGLT2 inhibitors, antibiotics, steroids, immunosuppressants).
• Biopsy if not responding to antifungal therapy.

• Keep the fold dry and exposed to air, and avoid occlusive clothing. Use a cool hair dryer or absorbent powder (a starch free powder, or miconazole 2% powder) in the fold.
• Topical antifungal therapy for 2 to 4 weeks, continued for 1 week after clearing:
  • Clotrimazole 1% cream twice daily.
  • Miconazole 2% cream or powder twice daily.
  • Ketoconazole 2% cream once or twice daily.
  • Nystatin 100,000 units/g cream 2 to 3 times daily (useful in infants and pregnancy).
  • Terbinafine is less effective for Candida.
• A short course of mild steroid (hydrocortisone 1% twice daily for 3 to 7 days) with the antifungal reduces itch and inflammation, then stop to avoid skin atrophy.
• Oral therapy for extensive, recurrent, refractory or immunocompromised disease:
  • Fluconazole 150 mg orally once, repeated after 1 week, or 100 to 200 mg orally daily for 7 to 14 days. Child: 3 to 6 mg/kg once daily.
  • Itraconazole 100 to 200 mg orally daily for 7 to 14 days, taken with food (capsules).
  • Check liver tests with prolonged courses and review drug interactions (statins, warfarin, calcium channel blockers).
• Non-albicans Candida (C. glabrata, C. krusei): fluconazole is often ineffective, so use topical clotrimazole or nystatin, or itraconazole 200 mg daily, guided by culture and sensitivity.
• Recurrence prevention:
  • Control diabetes (target HbA1c below 53 mmol/mol, 7%), lose weight and treat hyperhidrosis.
  • Stop or review SGLT2 inhibitors, systemic steroids and unnecessary antibiotics.
  • For frequent relapses, fluconazole 150 mg orally once weekly for 4 to 6 weeks.
• Special groups:
  • Pregnancy: use topical clotrimazole, miconazole or nystatin. Avoid oral fluconazole at high or repeated doses.
  • Infants: use nystatin or miconazole 2% cream at each diaper change, with barrier cream.
  • Renal impairment: reduce fluconazole dose by 50% if creatinine clearance is below 50 mL/min.
  • HIV and immunosuppression: treat for the full duration, optimise antiretroviral therapy and expect relapse.
• Follow up: review at 2 weeks. If there is no response, re-examine for tinea, erythrasma, psoriasis, bacterial infection or malignancy, and take a culture and biopsy.