- skin biology
- signs and symptoms
- investigations
- conditions and diseases
Section Links
Psoriasis
- epidemiology
- signs and symptoms
- diagnosis
- pathophysiology
- causes and risk factors
- treatments
- course
- patient education
- community resources
- references
Epidemiology
Psoriasis is a common chronic inflammatory condition affecting 1-2% people of all ages.
Signs and Symptoms
Psoriasis is sometimes accompanied by:
- arthritis
- myopathy
- enteropathy (?)
- spondylitic joint disease
- AIDS
Psoriasis most commonly affects the skin of the elbows, knees, scalp, lumbosacral areas, bum cleft, and penis.
Typical lesions are well-demarkated, pink to salmon-coloured, covered by loosely adherent scales characteristically silver-white.
Nail changes occur in 30% of cases of psoriasis, leading to yellow-brown discoloration with pitting, dimpling, and separation of the nail bed (oncholysis)
Diagnosis
Pathophysiology
Psoriasis is a T cell mediated disease, involving keratinocyte proloferation accompanying inflammation and angiogenesis.
There is a strong association between psoriasis and HLA-C.
It is likely that CD4+ cells initiate the disease by interacting with antigen-presenting cells, activating epidermal CD8+ cells. This interaction gives rise to many cytokines, dominated by IL-12, IFN-g, and TNF. TNF is apparently responsible for much of the pathogenesis.
New plaques may develop at areas of skin trauma.
Causes and Risk Factors
The antigen remains elusive.
Treatments
TNF antagonists can provide significant improvement in patients with psoriasis.
Course
Patient Education
Community Resources