Seborrheic Dermatitis



  • Seborrheic dermatitis (SD) is a common, multifactorial skin disease influenced by both host and environmental factors.
  • Involves sebaceous areas of the body
    • Including the scalp, face, back, chest, and intertriginous areas
    • Characterized by greasy, yellow, scaly erythematous lesions
  • Usually a self-limited condition in infants but can be a chronic, relapsing condition in adolescents and adults


  • Trimodal distribution: infants, adolescents, and adults >50 years of age
  • Highest prevalence between 2 weeks and 3 months of life
  • Affects approximately 10% of the general population and up to 70% of infants in the first 3 months of life
  • No sex predilection in infants; however, in adolescents and adults, males are affected more commonly than females.
  • Seasonal pattern: Prevalence of disease increases in winter months.
  • Strong association between Malassezia species, a common commensal organism, and SD

Risk Factors

  • There are no known genetic factors that contribute to disease.
  • Hormonal effects: exposure to maternal estrogen in infancy and surge of androgens in puberty
  • Use of neuroleptic medications
  • Immunocompromised status
    • Impaired cellular immunity may contribute to pathogenesis of disease.
    • Prevalence of SD in immunocompromised patients is significantly higher than in general population.

General Prevention

There are no known preventive measures.


  • Unknown, but suspected role of sebum, Malassezia, and inflammatory factors
  • Androgens stimulate sebaceous glands, causing production of more sebum.
  • Malassezia
    • A lipophilic yeast that is normally found in sebum-rich areas of the skin
    • Can break down skin sebum lipids, producing potentially inflammatory fatty acids
  • In response to the inflammatory fatty acids, keratinocytes produce proinflammatory cytokines.


Not completely known, although it is hypothesized that yeast, androgens, and the local host immune response play a role in SD development.

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