Psoriasis Signs and Symptoms

Last updated: 12 March 2025
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Introduction

  • Psoriasis is a systemic, chronic, inflammatory disorder that can be transmitted genetically and provoked by environmental factors
    • Found in approximately 2% of the population
      • Prevalence ranged from 0.5-11% in adults and 0-1.4% in children
    • Primarily affects the skin and joints
    • Associated with other inflammatory disorders and autoimmune diseases (eg psoriatic arthritis, inflammatory bowel disease, coronary artery disease)
    • Characterized by recurrent exacerbations and remissions

Signs and Symptoms

General

  • Begins as red scaling papules that coalesce to form round-to-oval plaques
  • Rashes are often pruritic and may be painful

Plaque Psoriasis

  • Also known as psoriasis vulgaris
  • Most common form of psoriasis approximately affecting 80-90% of patients
  • Scaling, erythematous, well-demarcated and silvery plaques with various sizes ranging from 1 cm to several centimeters
  • Plaques are irregular, round to oval in shape and tend to be symmetrically distributed
  • Typically affected areas: Elbows, knees, scalp, trunk, intergluteal cleft, buttocks, soles and palms
    • Occasionally, genitalia may also be affected 
  • Painful fissuring within plaques can occur when lesions are present over joint lines, palms and soles

Guttate Psoriasis

  • Common in persons <30 years old and affects <2% of patients with psoriasis
  • Usually occurs after an upper respiratory infection with group A beta-hemolytic streptococci
  • Teardrop-shaped, salmon-pink papules usually within a fine scale measuring 1-10 mm
  • Usually found on the trunk and proximal extremities
  • May be the first manifestation of psoriasis in a healthy individual or an acute exacerbation of long-standing plaque

Pustular Psoriasis

  • Generalized
    • Also called von Zumbusch psoriasis
    • Characterized by sterile pustules on an erythematous base that cover large portions of the trunk and extremities
    • Pustules may coalesce and form large pools of pus in severe cases
    • Skin’s protective functions are lost and patient is susceptible to infection, loss of fluids and nutrients
    • Uncommon, severe form of psoriasis associated with systemic symptoms (eg fever, malaise); can be life-threatening 
  • Localized
    • Pustules are localized to the palms and soles of the feet; may also localize on top of plaque
    • Not life-threatening but debilitating because of difficulty in using hands or feet

Erythrodermic Psoriasis

  • Severe, generalized erythema affecting up to 100% of the body surface area (BSA) with various degrees of scaling
  • Skin’s protective functions are lost and patient is susceptible to infection, uncontrollable body temperature, loss of fluids and nutrients
  • Often associated with systemic symptoms (eg fever and malaise); can be life-threatening

Inverse Psoriasis

  • Lesions consist of erythematous plaques with minimal scales
  • Located in the skin folds (eg axillary, genital, perineal, intergluteal, inframammary areas)

Pathogenesis

  • A complex immune-mediated inflammatory disease involving T lymphocytes, dendritic cells and cytokines (eg interleukin [IL]-23, IL-17, and tumor necrosis factor [TNF]) causing hyperproliferation and abnormal differentiation of the epidermis, infiltration of inflammatory cells, and vascular dilatation in genetically susceptible patients