A 6-month-old boy is brought to the office for evaluation of a progressive facial rash that started 3 weeks ago near his eyebrows and spread to areas of the face and scalp. The rash does not appear to be painful or pruritic. The mother recently started using a mild, unscented shampoo that slightly improved the scalp rash. Physical examination of the scalp is shown in the exhibit. In addition, erythematous, scaly plaques are on the eyebrows, nasolabial folds, and behind the ears. Which of the following is the most likely diagnosis?

Question

A 6-month-old boy is brought to the office for evaluation of a progressive facial rash that started 3 weeks ago near his eyebrows and spread to areas of the face and scalp.  The rash does not appear to be painful or pruritic.  The mother recently started using a mild, unscented shampoo that slightly improved the scalp rash.  Physical examination of the scalp is shown in the exhibit.  In addition, erythematous, scaly plaques are on the eyebrows, nasolabial folds, and behind the ears.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec25c8_d64b_a0bc_bc81_97de238caafb_MD0003_00 This patient has features typical of seborrheic dermatitis (SD). Incidence of SD peaks in the first year of life and again in adulthood. SD is associated with colonization by Malassezia species and primarily affects areas with numerous sebaceous glands. In infants, these areas include the scalp ("cradle cap") (red circle), eyelids, nasolabial folds, postauricular area, and umbilicus. infants scalp ("cradle cap") The diagnosis of SD is based on characteristic examination findings of erythematous patches and plaques with yellow, oily scales, and mild pruritus may be present. Treatment is not always necessary as spontaneous resolution is common. First-line treatment for children includes gentle emollients and non-medicated shampoos. Widespread or recalcitrant SD is managed with low-potency glucocorticoid creams or topical ketoconazole. (Choice A) Atopic dermatitis is a recurrent rash that can affect the cheeks, scalp, trunk, and extensor surfaces in infants. In contrast to SD, atopic dermatitis is associated with severe pruritus, and most patients will have a family history of atopic disorders (eg, asthma, allergic rhinitis). Atopic dermatitis (Choice B) Contact dermatitis is an inflammatory skin condition caused by contact with an allergen or irritant. Symptoms are similar to atopic dermatitis (including severe pruritus), although they are typically confined to a specific exposed area (eg, perioral area, hands). Contact dermatitis (Choice C) Psoriasis is a chronic inflammatory disorder that affects the extensor surfaces of the elbows and knees, but occasionally involves the scalp. Red, sharply demarcated, scaling lesions that coalesce to form round or oval plaques are classic presentations. Onset typically occurs in adulthood. Psoriasis (Choice E) Tinea capitis is a fungal infection of the scalp that causes pruritic patchy, fine, white scales that may resemble SD. However, it does not involve the eyebrows or nasolabial folds and is uncommon in the first year. Tinea capitis Educational objective: Seborrheic dermatitis in infants is characterized by a scaly, oily rash affecting the scalp, eyelids, nasolabial folds, postauricular area, and umbilicus. Spontaneous remission is common. First-line treatment options include emollients and nonmedicated shampoos. References: Diagnosis and treatment of seborrheic dermatitis. (http://www.ncbi.nlm.nih.gov/pubmed/25822272)

A 6-Month-Old Boy Is Brought to the Office for Evaluation