Psoriasis is a topic covered in the 5-Minute Emergency Consult.

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  • Chronic, noncontagious, inflammatory skin condition
  • Disease of hyperproliferation
  • Recently classified as an autoimmune disease
  • Presents with erythematous plaques with silver scaling
  • Most commonly affects the elbows, knees, lumbar area, gluteal cleft, and glans penis
  • Up to 1/3 of patients develop associated arthritis and 10% have ocular manifestations
  • Course is unpredictable; marked variability in severity over time and remissions may be seen
  • Exact cause unclear: triggers may be infectious, stressors, medications, or trauma
  • Tends to show improvement in summer months, possibly related to UV exposure
  • Associated with metabolic syndrome
  • Caucasians and atopics most affected
  • 2 peaks of onset: between ages 20–30 and 50–60
  • Affects 2.2% of US population, slightly higher incidence in females
  • Rare cause of mortality, but at least 100 deaths annually in US related to severe disease and/or treatment adverse effects
  • Several clinical presentations:
    • Plaque-type psoriasis (psoriasis vulgaris):
      • Most common form (75–80%) with erythematous, raised plaques with well-demarcated borders distributed over the scalp, back, and extensor side of the knees and elbows
    • Guttate psoriasis:
      • Abrupt appearance of multiple, discrete, salmon-colored, “drop-like” papules with a fine scale in a patient with no prior history of psoriasis
      • Most commonly seen on the trunk and proximal extremities
      • Often preceded by a streptococcal infection and resolves spontaneously
    • Pustular psoriasis:
      • Occasionally isolated to the palms and soles, but can present as widespread erythema, scaling, and sheets of superficial pustules with erosions
      • Patient may appear toxic and have other systemic symptoms, like malaise, fever, and diarrhea
      • Potentially severe and life threatening and treated as an inpatient if generalized
    • Erythrodermic psoriasis:
      • Generalized erythema and pruritis with a fine scale
      • Increased risk for infection, dehydration
      • Often treated as inpatients
    • Nail psoriasis
      • Pitting over the nail plate or change in nail bed
      • Nail changes in up to 50% of patients
    • Inverse flexural psoriasis:
      • A variant that causes lesions in flexural areas and in skin folds that do not exhibit scaling due to moisture in these areas
    • HIV-induced psoriasis:
      • May be the first manifestation of AIDS, more frequent and severe in HIV population
  • Genetics:
    • There is a genetic predisposition and gene loci have been identified
    • 40% of patients with psoriasis have a family history in a 1st degree relative


  • Typical findings of erythema and scaling are the result of increased number of epidermal stem cells and keratinocytehyperproliferation, shortened cell cycles, inflammatory infiltrates, and vascular changes
  • Triggers include:
    • Drugs:
      • Lithium
      • β-blockers
      • Antimalarials
      • Steroid withdrawal
      • NSAIDs
      • Alcohol
      • Potassium iodide
    • Infections:
      • Streptococcal pharyngitis
      • HIV
      • Staph
    • Local trauma:
      • Frostbite
      • Sunburn
      • Recent skin trauma (Koebner phenomenon)
    • Stress: Emotional and physical
    • Winter:
      • Low light exposure
      • Dry weather
    • Cigarette smoking
    • Elevated BMI

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