Treatment of Scabies in the Diaper Area with Co-existing Yeast Infection
Treat both conditions simultaneously: apply permethrin 5% cream to the entire body including the diaper area (from neck to soles of feet, including scalp in infants) for 8-14 hours, and apply a topical antifungal (nystatin or an imidazole) to the diaper area twice daily for the yeast infection. 1, 2, 3, 4
Scabies Treatment in Infants and Diaper Area
- Permethrin 5% cream is the first-line treatment for scabies in infants and young children, applied to all areas of the body from the neck down and washed off after 8-14 hours 1, 2, 5, 3
- Critically, infants require application to the scalp, temple, forehead, and hairline in addition to the rest of the body, as these areas are commonly infested in this age group (unlike adults) 3
- The diaper area must be thoroughly treated as part of the whole-body application 3
- One application is generally curative, though retreatment after 2 weeks may be necessary if live mites are observed 2, 3
- Oral ivermectin is contraindicated in children weighing less than 15 kg due to neurotoxicity risk 2, 5
- Lindane must be avoided in children under 10 years of age due to risk of seizures and neurotoxicity 1, 2, 5
Concurrent Yeast Infection Treatment
- Candida albicans is responsible for more than 80% of secondary fungal infections in the diaper area, taking advantage of the moisture, friction, and altered pH from urine and feces 4
- Apply topical antifungals (nystatin, imidazoles like clotrimazole or miconazole, or ciclopirox) to the diaper area twice daily for the yeast infection 4
- The antifungal can be applied to the diaper area after the permethrin has been washed off, and continued for 7-14 days until the yeast infection resolves 4
- Distinguish candidiasis from dermatophytosis clinically: dermatophytes (especially Epidermophyton floccosum) can also infect the diaper area but have different clinical characteristics 4
Critical Application Instructions to Avoid Treatment Failure
- Apply permethrin under the fingernails and toenails, and to the edges of all body orifices 2
- Use approximately 30 grams for an average adult; adjust proportionally for infants 3
- Do not apply permethrin immediately after bathing, as this increases systemic absorption and toxicity risk 1, 2
- Avoid contact with eyes; flush immediately with water if contact occurs 3
Management of Contacts and Environment
- Treat all household members, close contacts, and sexual contacts from the preceding month simultaneously, even if asymptomatic, as failure to do so is the most common cause of treatment failure 1, 2, 5
- Decontaminate all bedding and clothing by machine washing and drying with hot cycle, dry cleaning, or removing from body contact for at least 72 hours 1, 2, 5
- Fumigation of living areas is unnecessary 1, 2
Follow-Up and Persistent Symptoms
- Pruritus may persist for up to 2 weeks after successful treatment and does not indicate treatment failure 2, 5, 3
- Approximately 75% of patients with persistent itching at 2 weeks will have resolution by 4 weeks 3
- Retreatment is indicated only if live mites are demonstrable after 14 days, not for persistent itching alone 2, 3
- The yeast infection should show improvement within 3-5 days of antifungal treatment; if not, consider resistant strains or alternative diagnoses 4
Important Caveats
- Permethrin may temporarily exacerbate pruritus, edema, and erythema in the first few days after application 3
- Recent evidence suggests emerging permethrin resistance in some geographic areas, with one 2024 study showing only 27% cure rate with permethrin versus 87% with benzyl benzoate 25% 6
- If treatment fails after proper application and contact treatment, consider benzyl benzoate 25% as an alternative, though it causes burning sensation in 43% of patients 6
- Distinguish scabies-related skin changes from the yeast infection and irritant diaper dermatitis to ensure both conditions are adequately addressed 4