Seborrheic dermatitis is a common chronic inflammatory skin condition that affects areas with high sebaceous activity (e.g., scalp). The etiology remains unknown, but microbial colonization of the skin (esp. Malassezia), immunological factors, climate, or stress have been implicated. This condition is characterized by intermittent flares with intervening asymptomatic periods. Patients may exhibit either an erythematous, patchy scaling, or greasy yellow crusts, both of which could be associated with burning or itching. Early treatment of acute flares with topical glucocorticosteroids is recommended. Topical ketoconazole is used to relieve symptoms. The condition tends to recur over a lifetime despite treatment. Infantile seborrheic dermatitis (also referred to as “cradle cap”) is a subtype of seborrheic dermatitis and appears shortly after birth, primarily affecting the scalp. As opposed to seborrheic dermatitis in adults, it usually heals without treatment after a few months.
- Sex: ♂ > ♀
- Bimodal distribution: infants 2 weeks to 12 months; puberty and early adulthood.
- Prevalence: approximately 3–5% of general population worldwide
Epidemiological data refers to the US, unless otherwise specified.
- Unknown etiology; may be associated with Malassezia species
- Predisposing factors
- The pathophysiology is not yet fully understood
- Endogenous precipitants; : psychological stress; , fatigue, sleep deprivation, and hormonal changes
- Exogenous precipitants; : climate (the condition improves in the summer months and worsens in winter; ), trauma (e.g., excoriation of the skin from scratching), medication
- Chronic course with episodic, active phases (associated burning and itching) alternating with inactive, asymptomatic periods
- Ranges from erythematous plaques with patchy scaling → greasy yellow crusts, distributed along areas with hair and oily skin:
- Primarily a clinical diagnosis
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- : Lesions are usually dry in atopic dermatitis, rather than greasy as in seborrheic dermatitis.
- : The rash distribution reflects the areas and shapes of external exposure.
The differential diagnoses listed here are not exhaustive.
- Exposure to sunlight may help relieve symptoms.
- Avoid precipitating factors if possible
- Medical therapy
Steroidal creams should only be used for short periods because long-term use increases the risk of recurrences.
We list the most important complications. The selection is not exhaustive.
- No cure: often a chronic, recurrent course
- The active phases of seborrheic dermatitis are easily controllable with treatment
Special patient groups
Infantile seborrheic dermatitis
- Onset: occurs shortly after birth
- Clinical features
- Usually a clinical diagnosis
- Differential diagnosis
- Complications (rare)