Description

• Diaper dermatitis is a rash occurring under the covered area of a diaper (named for typical location, not etiology). It is usually initially a contact irritant dermatitis but can be caused by or contributed by systemic conditions.
• Rarely, a serious condition, but patient discomfort and caregiver anxiety are considerations.
• System(s) affected: skin/exocrine
• Synonym(s): diaper rash; nappy rash; napkin dermatitis

Geriatric Considerations
Incontinence is a significant cofactor in the elderly population.

Epidemiology

Incidence

• The most common dermatitis is found in infancy.
• Peak incidence: 7 to 12 months of age and then decreases
• Lower incidence is reported in breastfed babies due to lower pH, urease, protease, and lipase activity.

Prevalence
Prevalence has been variably reported from 4–35% in the first 2 years of life. Upward of 75% of infants will have episodes of varying duration and severity in United States. Severity varies: 58% slight symptoms; 34% moderate; 8% severe. Underreporting contributes to difficulty in determining impact of condition.

Etiology and Pathophysiology

• Immature infant skin with histologic, biochemical, functional differences compared to mature skin
• Wet skin is central in the development of diaper dermatitis, as prolonged contact with urine or feces results in susceptibility to chemical, enzymatic, and physical injury; wet skin is also penetrated more easily.
• Fecal proteases and lipases are irritants.
• Superhydrase urease enzyme found in the stratum corneum liberates ammonia from cutaneous bacteria.
• Fecal lipase and protease activity are increased by acceleration of GI transit; thus, a higher incidence of irritant diaper dermatitis is observed in babies who have had diarrhea in the previous 48 hours.
• Once the skin is compromised, secondary infection by Candida albicans is common. 40–75% of diaper rashes that last >3 days are colonized with C. albicans.
• Bacteria may play a role in diaper dermatitis through reduction of fecal pH and resulting activation of enzymes.
• Allergy is exceedingly rare as a cause in infants.

Risk Factors

• Infrequent diaper changes
• Improper laundering (cloth diapers)
• Family history of dermatitis
• Hot, humid weather
• Recent treatment with oral antibiotics
• Diarrhea (>3 stools per day increases the risk.)
• Dye allergy
• Eczema may increase the risk.

General Prevention

Most effectively managed by prevention including rigorous attention to hygiene

Commonly Associated Conditions

• Contact (allergic or irritant) dermatitis
• Seborrheic dermatitis
• Psoriasis
• Candidiasis
• Atopic dermatitis