Interdigital Candidiasis

Interdigital candidiasis is a Candida infection of the web spaces of the fingers or toes, most often the third web space of the hand in people with prolonged wet exposure. It is also called erosio interdigitalis blastomycetica.

• Risk factors: wet occupations (cleaners, dishwashers, farmers, barbers, healthcare), diabetes, obesity, occlusive footwear or gloves, HIV, steroid use.
• Warm, moist and macerated skin favours Candida growth.

Soggy white macerated skin with erythematous fissured erosions in the web space and collarette scale, burning or itch.

• Often involves the third and fourth finger web spaces, sometimes with chronic paronychia.
• Differential diagnosis: tinea pedis, erythrasma, bacterial intertrigo (Pseudomonas, staphylococcus), contact dermatitis, dyshidrotic eczema, psoriasis, dermatophyte infection, scabies.
• Complications: secondary bacterial infection and cellulitis, chronic paronychia and nail dystrophy, lymphangitis, recurrence, spread to other intertriginous sites.

Clinical with skin scraping for KOH and culture.

• Glucose or HbA1c, HIV test where indicated; bacterial swab if purulent.
• Wood lamp (coral red in erythrasma) helps to exclude it.

Keep dry and apply topical antifungals.

• Supportive: dry between the digits after washing, wear cotton lined gloves under waterproof gloves, avoid prolonged moisture, open footwear, cotton or wool socks, change gloves and socks regularly, weight loss.
• Pharmacological: clotrimazole 1 percent, miconazole 2 percent or econazole 1 percent cream twice daily for 2 to 4 weeks; nystatin cream 100,000 units/g twice daily; aqueous gentian violet 0.5 percent twice daily for 3 days where available; drying agents such as aluminium acetate soaks 1 in 20 for 20 minutes twice daily during weeping. For extensive or recurrent disease: fluconazole 150 mg weekly for 2 to 4 weeks, or itraconazole 100 mg daily for 14 days. Add fusidic acid 2 percent cream three times daily for bacterial infection.
• Procedures: none.
• Special groups: pregnancy, topical clotrimazole or miconazole; children, topical treatment and drying; diabetes, strict glucose control and foot care; immunosuppressed, longer therapy.
• Red flags: spreading cellulitis, lymphangitis, fever, non healing ulcer, black discolouration (gangrene in diabetes).
• Follow-up: review at 2 weeks; advise on occupational moisture avoidance.