Diaper Rash

Diaper rash is inflammatory dermatitis of the skin covered by a diaper (nappy), also called napkin or nappy dermatitis. Affects up to 25 to 65 percent of infants, peaking at 9 to 12 months, and also affects incontinent older children and adults.

• Causes (often multifactorial):
  • Irritant contact dermatitis (commonest, over 75 percent): prolonged contact with urine and faeces (faecal enzymes, ammonia, raised skin pH, wetness related maceration), friction, diarrhoea, infrequent changes, harsh wipes, soaps and detergents.
  • Candidal diaper dermatitis (Candida albicans): secondary infection of macerated skin, especially after 3 days of rash, with oral thrush, recent antibiotics, diarrhoea.
  • Bacterial infection (Staphylococcus aureus impetigo, perianal streptococcal dermatitis, Group A streptococcus).
  • Seborrhoeic dermatitis, atopic dermatitis, psoriasis (napkin psoriasis), allergic contact dermatitis (preservatives, fragrance, topical agents), miliaria.
  • Less common: herpes simplex (erosions), zinc deficiency (acrodermatitis enteropathica), biotin deficiency, Langerhans cell histiocytosis, scabies, Kawasaki disease (perineal desquamation), child abuse (burns), HIV or immunosuppression, infantile gluteal granuloma (from topical steroids).
• Risk factors: diarrhoea, introduction of solid food, antibiotic use, infrequent changes, super absorbent diapers used improperly, occlusive plastic pants, bottle feeding, skin disease, immune deficiency.
• Complications: secondary infection, ulceration (Jacquet erosive dermatitis), pain, sleep disturbance, urinary tract infection (rare), scarring.

• Irritant dermatitis: erythema, scaling, papules, and sometimes erosions over convex surfaces (buttocks, genitals, lower abdomen, upper thighs), sparing skin folds ("W" pattern). Mild: pink; moderate: red, papules; severe: erosions, ulcers, weeping.
• Candida: bright red, beefy plaques with well demarcated borders, involvement of skin folds, satellite pink papules and pustules, collarette scale; often with oral thrush.
• Seborrhoeic: salmon pink greasy scale including folds, with scalp scale.
• Psoriasis: sharply demarcated, glazed red plaques, including folds.
• Bacterial: honey coloured crusts, bullae, pustules, perianal redness with pain on defecation (streptococcal).
• Red flags: vesicles, punched out erosions (herpes), widespread desquamation with fever (staphylococcal scalded skin syndrome, Kawasaki), persistent rash despite therapy for 2 weeks, severe or ulcerated rash, rash with failure to thrive or diarrhoea (zinc deficiency), purpura, nodules, hepatosplenomegaly (histiocytosis), injuries or burns with inconsistent history, immunodeficiency, systemic illness.

• Clinical, based on appearance and distribution.
• Skin swab for bacterial culture or potassium hydroxide preparation and Candida culture if pustules, satellite lesions, or failure to respond to 3 days to 1 week of barrier care.
• Herpes simplex PCR for vesicles or punched out erosions.
• Skin biopsy for persistent, atypical or nodular lesions; zinc and alkaline phosphatase levels if acral and perioral dermatitis; patch testing for allergic contact dermatitis.

• Prevention and basic care (all stages):
  • Change diapers promptly, at least every 2 to 3 hours in the day and once at night when soiled; use super absorbent disposable diapers; allow diaper free periods (air exposure) for 10 to 20 minutes several times daily.
  • Clean gently with warm water and cotton wool or a soft cloth, or fragrance free alcohol free wipes; pat dry (do not rub); avoid soap, bubble bath, talc and powders (inhalation risk) and over washing; do not use hairdryers.
  • Apply a thick barrier cream or ointment at each change: zinc oxide 10 to 40 percent paste, white soft paraffin, dimeticone, or petrolatum.
  • Diaper size not too tight; avoid plastic pants.
• Mild irritant dermatitis: continue frequent changes, air exposure and a thick barrier cream; reassess in 2 to 3 days.
• Moderate to severe irritant dermatitis not responding: hydrocortisone 1 percent cream or ointment applied thinly once or twice daily for up to 7 days (avoid potent steroids in the diaper area because of absorption and atrophy).
• Candidal dermatitis: topical antifungal with each diaper change for 7 to 14 days, continued 2 days after clearance:
  • Clotrimazole 1 percent cream twice daily; or miconazole 2 percent cream (or ointment) twice daily; or nystatin 100,000 units/g cream or ointment 3 to 4 times daily.
  • Combine with hydrocortisone 1 percent for 3 to 5 days if marked inflammation.
  • Treat oral thrush simultaneously: miconazole 2 percent oral gel 1.25 to 2.5 mL four times daily (children under 2 years: 1.25 mL four times daily; avoid in infants under 4 months), or nystatin suspension 100,000 units/mL 1 mL four times daily after feeds for 7 days and 2 days beyond resolution; treat breastfeeding mother's nipples if symptomatic.
  • Oral antifungal (fluconazole 3 to 6 mg/kg once daily) only for recurrent or severe cases by a specialist.
• Bacterial infection: mupirocin 2 percent ointment or fusidic acid 2 percent cream three times daily for 5 to 7 days for localised lesions; oral flucloxacillin 12.5 to 25 mg/kg four times daily (maximum 500 mg per dose) for 7 days or cefalexin 12.5 to 25 mg/kg twice daily for extensive impetigo or perianal streptococcal dermatitis (penicillin V 12.5 mg/kg four times daily for 10 days for streptococcus).
• Herpes simplex: aciclovir (specialist); psoriasis and seborrhoeic dermatitis: gentle emollients, low potency steroid, ketoconazole 2 percent cream.
• Diarrhoea: treat the cause and change diapers immediately; use zinc oxide thickly.
• Avoid topical steroid-antifungal-antibiotic combination creams, boric acid, powder, and irritant ingredients (benzocaine, diphenhydramine, camphor, salicylates).
• Review at 3 to 7 days; refer for non-response by 2 weeks, atypical features, or recurrent episodes; consider zinc and immune assessments.