A 3-month-old boy presents for evaluation of a diffuse asymptomatic rash that began on his scalp (Figure 1) and skin creases 6 weeks ago and has spread over his trunk and extremities (Figure 2). This week he has begun to scratch at his neck and abdomen.
Diagnosis: Seborrheic dermatitis
The pattern, morphology, and symptoms associated with rashes in young infants help to establish the diagnosis and treatment regimen. Atopic dermatitis (AD) and seborrheic dermatitis (SD) present commonly in early infancy and clinical features can overlap, leading to a delay in diagnosis and effective management (Table).
Seborrheic dermatitis has a prevalence of 4% in infants aged younger than 5 years.1 Within the first 3 months, SD often manifests as “cradle cap” with erythematous scaly plaques beneath a thick yellow greasy exudate. Other common sites have been coined the “seborrheic areas,” notably the face, neck, and groin. Such areas have a high density of sebaceous glands. Infant SD is not associated with significant morbidity as symptoms are often mild and self-limiting, resolving by age 12 months.2
Almost one-quarter of pediatric patients referred to pediatric dermatologists have AD.3 A majority (90%) of patients are aged younger than 5 years at presentation. Many develop symptoms within the first 3 months of life; and onset may overlap with SD. Unlike SD, AD is a chronic condition with intermittent flares that has a significant impact on a developing child’s quality of life.
Atopic dermatitis manifests as an erythematous eruption with intense pruritus. The lesions in young children tend to be moist and crusted, becoming less exudative with increasing age. This picture can be easily confused with SD, and AD may develop concurrently. Both AD and SD can be associated with hypopigmentation and/or hyperpigmentation, but lichenification, excoriations, and sparing of protected areas (eg, intertriginous and diaper areas) are typical of AD in infancy.3
1. Schachner L, Ling NS, Press S. A statistical analysis of a pediatric dermatology clinic. Pediatr Dermatol. 1983;1(2):157-164.
2. Alexopoulos A, Kakourou T, Orfanou I, Xaidara A, Chrousos G. Retrospective analysis of the relationship between infantile seborrheic dermatitis and atopic dermatitis. Pediatr Dermatol. 2014;31(2):125-130.
3. Lapidus C, Honig PJ. Atopic dermatitis. Pediatr Rev. 1994;15(8):327-332.
4. Clark GW, Pope SM, Jaboori KA. Diagnosis and treatment of seborrheic dermatitis. Am Fam Physician. 2015;91(3):185-190.
5. Lyons JJ, Milner JD, Stone KD. Atopic dermatitis in children: clinical features, pathophysiology, and treatment. Immunol Allergy Clin North Am. 2015;35(1):161-183.