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Basics ⬇

Seborrheic Dermatitis (See also Chapter 13: Eczema and Related Disorders)

Pathogenesis ⬆ ⬇

Clinical Manifestations ⬆ ⬇

Infancy !!navigator!!

  • In infancy, SD typically appears at 3 to 4 weeks of life (range 1 to 10 weeks), with yellowish-brown, greasy adherent scales on the vertex and anterior scalp and is often called “cradle cap” (Fig. 4.24).

  • SD can then progress to an erythematous scaly eruption involving the entire scalp.

  • In infants, the scalp is almost always involved. Other areas of the body are variably involved.

  • On the face, infantile SD appears as pink-orange greasy patches with varying amounts of overlying scale.

  • On the body, well-demarcated pink to salmon-colored, shiny patches with greasy scale are seen on the retroauricular folds, trunk, and in the body folds including the axillae and inguinal folds (Fig. 4.25).

  • Unlike atopic dermatitis, pruritus is usually slight or absent.

  • Some infants with SD progress into atopic dermatitis.

Adolescence !!navigator!!

  • In adolescence, SD usually appears on the scalp and as erythema and scaling and is often called “dandruff.” The face and body can also be affected.

  • In severe cases, scaling can be thick and adherent and mimic psoriasis and is termed “sebopsoriasis” (see Chapter 14: Psoriasis).

  • On the body, lesions typically appear on the face specifically the forehead, eyebrows, eyelashes, cheeks, beard, and nasolabial folds (Fig. 4.26) as variable amounts of erythema and greasy scaling. In the body folds (i.e., retroauricular folds, inframammary areas, axillae, inguinal creases, intragluteal crease, perianal area, and umbilicus) or in the presternal skin, lesions of SD appear as well demarcated pink-orange greasy patches with or without an overlying whitish scale.

  • The eruption of SD tends to be bilaterally symmetric.

  • SD is seen more commonly seen in boys.

Outline

Clinical Variant ⬆

  • On the scalp, there may be itching and scratching which can lead to significant scale that is often noticeable on clothing.

  • Occasionally, secondary candidal or bacterial infection can occur in SD and the neck fold and the inguinal folds are most susceptible.

  • When infection is suspected, bacterial culture should be sent and topical anticandidal and/or antibacterial agents should be initiated. Topical agents are generally sufficient to clear an infection; however, occasionally systemic antibiotics are necessary.

  • Pityriasis amiantacea (also called tinea amiantacea although it is not a fungal infection), a condition of thick plate-like scales firmly adherent to the scalp and hair (Fig. 4.27), can develop in untreated SD of the scalp.

Diagnosis-icon.jpg Differential Diagnosis

The differential diagnosis of SD varies depending on the age, and the location of the lesions.

Infants
Atopic Dermatitis

  • AD presents later in infancy (2 to 3 months).

  • In AD, lesions are ill-defined, with dry scale and are very itchy.

  • Occluded “fold” areas of the body are usually spared in AD whereas, seborrheic dermatitis which typically involves folds.

Psoriasis

  • Infantile psoriasis often starts in the diaper area and can be difficult to distinguish from infantile seborrheic dermatitis.

  • Typical psoriatic lesions—well-demarcated bright pink red patches and plaques with overlying silvery white scale—may be present elsewhere.

Irritant Contact Dermatitis

  • Skin within the body folds is spared.

  • Shiny pink patches in areas of contact with the irritant, that is, convex surfaces of labia and buttocks in diaper dermatitis.

Candidiasis

  • Tends to occur in body folds but patches are brighter, more “beefy” red.

  • Pinpoint satellite pustules and a typical odor may be present.

  • KOH and fungal culture will be positive for Candida species.

Adolescents
Psoriasis

  • Scalp psoriasis can be difficult to distinguish from SD.

  • Well-demarcated plaques with silvery white scale.

  • Psoriatic plaques and nail pits may be present elsewhere.

Eczematous Dermatitis Such as Atopic Dermatitis

  • Eczematous lesions elsewhere on the body.

  • Atopic history.

  • Marked pruritus.

Tinea Capitis

  • Scale is drier.

  • Broken hairs may be present.

  • Occipital lymphadenopathy sometimes present.

Management-icon.jpg Management

Infants

  • SD in infants usually self resolves by 8 to 12 months of age.

  • No treatment is required; in extensive cases treatment can be used to alleviate symptoms.

Scalp

  • Frequent shampooing with a regular gentle baby shampoo usually suffices.

  • Removal of scales can be facilitated by massaging the affected area of scalp with baby oil or mineral oil.

  • Antifungal shampoos such as ketoconazole 2% are effective but should only be used as a last resort as they are drying and can irritate the eyes.

  • When redness is present the use of a low-potency topical steroid in a lotion, solution, or oil base such as hydrocortisone 2.5% or desonide 0.05% applied twice daily is effective.

Face and Body Folds

  • Either a low-potency topical steroid (class 5 to 7): hydrocortisone 2.5% or desonide 0.05% or topical antifungal agent: ketoconazole 2% cream or econazole 1% cream can clear SD when applied once to twice daily.

Adolescents

  • Treatment of SD in adolescents is similar to treatment in adults and is discussed in detail in Chapter 13: Eczema and Related Disorders.

  • Briefly, treatment of scalp SD involves frequent shampooing (at least four to five times per week) with shampoos that contain tar, salicylic acid, selenium sulfide, zinc pyrithione, or antifungal agents (i.e., ketoconazole). Alternative use of different preparations on a regular basis is recommended as part of a treatment regimen. Suggested shampoos include Sebulex, Selsun blue, T-sal, T-gel, Head & Shoulders, and DHS Zinc.

  • These antiseborrheic shampoos can also be used as body washes for SD on the body.

  • For associated erythema and/or pruritus, medium- to high-potency (class 1 to 3) topical steroid lotions, gels, oils, or foams (clobetasol 0.05% gel/lotion/solution/foam, fluocinonide 0.05% gel, fluocinolone 0.025% solution or betamethasone valerate foam 0.12% [Luxiq foam]) applied twice daily are effective. Foams, solutions, and gels are less oily than ointments or creams.

  • For SD on the face or in the body folds, a mild steroid (class 5 to 7) or a topical calcineurin inhibitor (i.e., Elidel cream) used twice daily can clear the redness, then an antifungal agent such as econazole 1% cream or ketoconazole 2% cream should be used on a daily basis as maintenance.

Helpful-Hint-icon.jpg Helpful Hints

  • Infantile seborrheic dermatitis presents in the first few weeks of life, affects skin folds, and subsides by 3 to 4 months of age; whereas atopic dermatitis presents later, at around 3 months of age, and affects the extensor surfaces and spares the folds.

  • SD of the scalp is generally not seen in preadolescent children; therefore, excessive use of shampoos should not be encouraged in this age group. The child may actually have atopic dermatitis, which is only aggravated by frequent shampooing.

  • The application of topical antifungals may work as well or better than topical steroids in many cases.

  • Protopic ointment (tacrolimus) 0.1% and Elidel cream (pimecrolimus) 1% may also be effective in the treatment of facial and intertriginous SD.

Point-Remember-icon.jpg Points to Remember

  • Infantile SD is often asymptomatic and self-resolves.

  • Low-potency topical steroids or topical antifungal agents can help reduce redness and scaling in infantile SD.

  • In adolescents, antiseborrheic shampoos should be used in combination with intermittent use of topical steroids.

SEE PATIENT HANDOUT “Scalp Psoriasis: Scale Removal” IN THE COMPANION eBOOK EDITION.