Seborrheic Dermatitis

Infantile form

  • Self-limited
  • First 3 months of life

Adult form

  • Chronic
  • 40-60 years old
  • Prevalence 5%
  • Males > Females
  • No genetic predisposition

  1. Malassezia furfur
  2. Active sebaceous glands:
    • Sebum overproduction- thought to be secondary to androgen activation, also contributing to Malassezia growth
  3. Sebum in seborrheic dermatitis:
    • Normal sebum 
      • Triglycerides
      • Cholesterol
      • Squalene
      • Free fatty acids
    • Seborrheic dermatitis 
      • Higher Triglycerides
      • Higher Cholesterol
      • Lower Squalene
      • Lower Free fatty acids
      • Free fatty acids: product of triglycerides and Propionibacterium acnes lipase (has antimicrobial activities)
      • Lower Propionibacterium acnes (imbalance of normal skin flora)

  • Well demarcated
  • Patches/thin plaques 
  • Pink-yellow, red-brown
  • “Greasy” scales
  • Areas with sebaceous glands
    • Scalp
    • Face
    • Ears
    • Presternal
    • ± Folds
  • Limited extend + minimal symptoms (erythroderma is rare)

Infantile form 

  • Greasy scales + crust
  •  ± Inflammation and oozing on scalp (“cradle cap”)
  • Involvement of
    • Axillae
    • Neck
    • Retroauricular folds
  • Superinfection
    • Candida app. 
    • Group A Streptococcus 

Adult form:

  • Dandruff (Pityriasis simplex capillitii)
    • Mild 
    • Seborrheic dermatitis without inflammation
  • Seborrheic dermatitis
    • Dandruff with inflammation and pruritus
    • Symmetrical involvement of a. Forehead
    • Eyebrows and eyelids
    • Nasolabial folds 
    • Retroauricular areas
  • Skin is sensitive to irritation, heat, sun
  • Chronic, relapsing course

If extensive/treatment resistant

  • Human immunodeficiency virus 
  • Parkinson disease
  • Cerebrovascular accidents
  • Mood disorders

  • Spongiosis
  • Superficial perivascular and perifollicular infiltrate of lymphocytes

Infantile form:

  • Self-limited
  • Skin care with bath and emollients
  • Low potency topical corticosteroids (↓ inflammation)
  • Avoid irritation
  • If extensive: ketoconazole 2% cream

Adult form:

  • Mainstay: topical azoles like ketoconazole (shampoo or cream)
  • Other: 
    • Ciclopirox (shampoo or cream)
    • Emollients
    • Low potency topical corticosteroids
    • Topical calcineurin inhibitors
    • Selenium sulfide
    • Tar/zinc shampoos