Where is psoriasis typically located on the body?

Common Locations of Psoriasis

Psoriasis typically presents on the scalp, elbows, knees, and presacral region, though any area of the skin may be involved, including the palms, soles, nails, and genitalia. 1, 2

Primary Distribution Patterns

Psoriasis has characteristic distribution patterns that help with diagnosis:

• Most common locations:

  • Scalp (affects approximately 50% of patients)
  • Elbows
  • Knees
  • Lower back/presacral region
  • Trunk
  • Intertriginous areas 2

• Special areas (often causing disproportionate physical and emotional distress):

  • Face
  • Genitals
  • Hands and feet
  • Nails
  • Intertriginous regions 2, 3

Clinical Significance of Location

The location of psoriasis has important clinical implications:

• Severity assessment: Psoriasis severity is not solely determined by body surface area (BSA). Even when affecting less than 3% BSA, psoriasis in special locations can be considered severe due to its impact on quality of life 2

• Treatment considerations: Different body areas require different treatment approaches:

  • Intertriginous areas require careful steroid use due to atrophy risk
  • Scalp psoriasis often requires specialized formulations for penetration
  • Facial and genital psoriasis requires lower-potency treatments 3

Clinical Forms and Their Distribution

Psoriasis presents in several clinical forms, each with characteristic distributions:

• Plaque psoriasis (psoriasis vulgaris): Most common form (>80% of cases), typically affecting elbows, knees, scalp, and trunk 4

• Flexural/inverse psoriasis: Affects skin folds with thinner lesions and minimal scaling 4

• Guttate psoriasis: Small, drop-shaped lesions often appearing suddenly after infection, widespread distribution 4

• Pustular psoriasis: Can be localized (palms and soles) or generalized 5

• Erythrodermic psoriasis: Generalized form affecting entire skin surface 4

Clinical Pearls

• Children with psoriasis may present with unique distribution patterns, including isolated facial or genital involvement, particularly in infancy 1

• Despite affecting small surface areas, psoriasis in special locations (face, genitals, hands, feet, nails) causes disproportionate physical and emotional distress 3

• A common pitfall is underestimating the severity of psoriasis affecting small but sensitive areas like the face or genitals 2

• The presence of psoriasis in certain locations may help distinguish it from other dermatological conditions with similar presentations 4