Where can psoriasis occur on the body?

Psoriasis Locations on the Body

Psoriasis can occur virtually anywhere on the body, with common locations including the scalp, elbows, knees, and presacral region, while special areas like the face, genitals, hands, feet, nails, and intertriginous regions often cause disproportionate physical and emotional distress despite affecting smaller surface areas. 1

Common Psoriasis Locations

Psoriasis can manifest in various locations on the body, each with unique characteristics:

Classic Plaque Psoriasis

• Extensor surfaces: Elbows and knees are classic locations 1
• Scalp: Affects approximately 50% of patients with psoriasis 1
• Trunk: Including periumbilical area and back 1
• Presacral region: Lower back area 1

Special Areas

These locations often cause significant quality of life issues despite affecting smaller body surface areas:

• Intertriginous/Inverse psoriasis: Affects skin folds with minimal scaling due to moisture 1

  • Axillary (underarm) areas
  • Genital and perineal regions
  • Intergluteal (between buttocks) areas
  • Inframammary (under breast) regions
  • Flexural surfaces (like antecubital fossae)

• Face: Can be particularly stigmatizing and psychologically distressing 2

• Nails: Occurs in approximately 50% of fingernails and 35% of toenails 1

  • Presents as pitting, onycholysis, subungual hyperkeratosis, and oil-drop sign
  • Up to 90% of patients with psoriatic arthritis have nail involvement

• Hands and feet: Including palmoplantar surfaces 2, 3

  • Localized pustular variant can specifically affect palms and soles 1

Psoriasis Types by Distribution Pattern

Different clinical variants of psoriasis have characteristic distribution patterns:

• Plaque psoriasis (vulgaris): Most common form, affecting elbows, knees, scalp, and trunk 1, 4

• Guttate psoriasis: Primarily affects trunk and proximal extremities with small "dew-drop-like" lesions 1

• Pustular psoriasis: Can be generalized or localized to palms and soles 1

• Erythrodermic psoriasis: Can affect nearly the entire body surface area 1

Clinical Implications of Location

The location of psoriasis has important implications:

• Treatment challenges: Areas like scalp, nails, and intertriginous regions are often more difficult to treat effectively 3

• Psoriatic arthritis risk: Involvement of scalp, nails, and intertriginous areas is associated with increased risk of psoriatic arthritis 5

• Quality of life impact: Even limited psoriasis in visible or sensitive areas can cause significant psychological distress and impairment 2

• Treatment selection: Location influences treatment choice - for example:

  • Intertriginous areas require careful steroid use due to atrophy risk 1, 3
  • Scalp psoriasis may benefit from specialized formulations 3
  • Nail psoriasis often requires systemic therapy for adequate response 5

Important Considerations

• Psoriasis severity is not solely determined by body surface area - location matters significantly 1, 2

• Even when affecting less than 5% of body surface area, psoriasis in special locations (face, genitals, hands, feet) can be considered severe 1

• Treatment approaches must be tailored to the specific location, considering both efficacy and potential side effects unique to each anatomical site 3