What is the most appropriate pharmacologic treatment for a 53-year-old patient with intertriginous candidiasis (fungal infection in skin folds) presenting with a moist, erythematous, and malodorous rash under the abdominal pannus?

From the Guidelines

The most appropriate pharmacologic treatment for intertriginous candidiasis under the abdominal pannus is a topical antifungal medication such as clotrimazole 1% cream, miconazole 2% cream, or ketoconazole 2% cream applied twice daily for 2-4 weeks. For this specific presentation with moist, erythematous, and malodorous characteristics, a combination product containing an antifungal plus a mild corticosteroid (like clotrimazole-betamethasone) may be beneficial for the first 7-10 days to address both the infection and inflammation. Alternatively, nystatin powder can help keep the area dry while treating the infection. The area should be kept clean and dry, with gentle washing using a mild soap, thorough drying, and possibly using a barrier cream or absorbent powder after antifungal application. For severe or recurrent cases, oral fluconazole 150 mg once weekly for 2-4 weeks may be necessary, as supported by the Infectious Diseases Society of America guidelines 1. These medications work by disrupting the fungal cell membrane or inhibiting ergosterol synthesis, which is essential for fungal cell integrity. Weight loss and proper hygiene are important adjunctive measures to prevent recurrence by reducing skin-to-skin contact in the fold areas. Key considerations in managing intertriginous candidiasis include:

• Maintaining dryness in the affected area
• Using topical antifungal agents as first-line treatment
• Considering oral antifungal therapy for severe or recurrent cases
• Addressing underlying factors such as obesity to prevent recurrence, as emphasized in the clinical practice guidelines for the management of candidiasis 1.

From the FDA Drug Label

CLINICAL PHARMACOLOGY Pharmacokinetics Nystatin is not absorbed from intact skin or mucous membrane. Microbiology Nystatin is an antibiotic which is both fungistatic and fungicidal in vitro against a wide variety of yeasts and yeast-like fungi, including Candida albicans, C. parapsilosis, C. tropicalis, C. guilliermondi, C. pseudotropicalis, C. krusei, Torulopsis glabrata, Tricophyton rubrum, T mentagrophytes. DOSAGE AND ADMINISTRATION Very moist lesions are best treated with the topical dusting powder. Adults and Pediatric Patients (Neonates and Older): Apply to candidal lesions two or three times daily until healing is complete.

The most appropriate pharmacologic treatment for the patient with intertriginous candidiasis is nystatin powder. This is because the patient's rash is described as moist and erythematous, and the drug label for nystatin recommends using the topical dusting powder for very moist lesions 2 2. Key points to consider in this decision include:

• The patient's symptoms are consistent with a fungal infection, and nystatin is effective against a wide variety of yeasts and yeast-like fungi.
• The use of nystatin powder is specifically recommended for moist lesions, which matches the patient's presentation.
• The patient should apply the powder to the affected area two or three times daily until healing is complete.

From the Research

Intertriginous Candidiasis Treatment

The patient's symptoms, including a moist, erythematous, and malodorous rash under the abdominal pannus, are consistent with intertriginous candidiasis. The most appropriate pharmacologic treatment for this condition is:

• Fluconazole oral: This is supported by a case report of a patient with cutaneous Candida tropicalis infection, which was resolved with fluconazole therapy 3.
• Nystatin cream or powder: Nystatin is also effective against candidal infections, as shown in a study comparing nystatin cream with a combination of nystatin and triamcinolone acetonide cream in the treatment of candidal inflammation of the flexures 4. Another study found that vaginal nystatin suppositories were effective in treating recurrent vulvovaginal candidiasis, including cases caused by C. glabrata or fluconazole-resistant Candida 5.
• Tea tree oil: There is no evidence in the provided studies to support the use of tea tree oil for the treatment of intertriginous candidiasis.

Comparison of Treatment Options

The studies suggest that both fluconazole and nystatin are effective against candidal infections. However, fluconazole may be more effective against certain species of Candida, such as C. tropicalis 3. Nystatin, on the other hand, may be more effective against C. glabrata or fluconazole-resistant Candida 5. The choice of treatment should be based on the specific characteristics of the patient's infection and medical history.

Antifungal Sensitivity

In vitro antifungal sensitivity testing has shown that fluconazole, clotrimazole, and nystatin have varying degrees of effectiveness against different species of Candida 6. Clotrimazole was found to be more effective than fluconazole and nystatin against C. albicans, while fluconazole was more effective against C. tropicalis. Nystatin was effective against a range of Candida species, including C. glabrata and C. krusei.