psoriasis
PSORIASIS

Psoriasis is a systemic chronic skin disorder characterized by excessive keratinocytes proliferation that results into thickened scaly plaques, itching and inflammatory changes in the epidermis and dermis. It is transmitted genetically but can be provoked by environmental factors.
It is found in approximately 2% of the population that primarily affects the skin and joints.
It is associated with other inflammatory disorders and autoimmune diseases (eg psoriatic arthritis, inflammatory bowel disease, coronary artery disease).
Generally, it begins as red scaling papules that coalesce to form round-to-oval plaques. The rashes are often pruritic and may be painful.

Introduction

  • Psoriasis vulgaris is a systemic, chronic, inflammatory disorder that can be transmitted genetically & provoked by environmental factors
    • Found in approximately 2% of the population
    • 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

  • 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 cms
  • 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)
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