Psoriasis is a chronic inflammatory condition affecting the skin and several organ systems. About a third of patients have family members with psoriasis. It is classified into several subtypes , but is characteristically identified by clearly defined, red areas covered with a thick, silvery scale. Treatment is prescribed according to severity and treatment response. Quality of life indexes and PASI scores are valuble tools in measuring treatment response.
What causes psoriasis?
Genetic factors and environmental triggers play an important role. The TH17 pathway is mainly involved. Triggers include infection, stress, alcohol, smoke and obesity, as well as certain drugs and withdrawal of steroids.
What are the clinical features of psoriasis?
Red, well-defined plaques with silvery white scale appear most commonly on the scalp, sacral area, elbows and knees. A mild itch is often reported and painful skin cracks may occur. Psoriasis may leave brown or pale marks.
Types of psoriasis
- Guttate psoriasis – widespread small plaques
- Plaque type psoriasis - affects elbows, knees and lower back
- Flexural psoriasis - smooth, well-defined patches in body folds
- Scalp psoriasis
- Nail psoriasis
Conditions associated with psoriasis
- Psoriatic arthritis
- Inflammatory bowel disease
- Cardiovascular risks
Treatment of psoriasis
- General advice
- Stop smoking, avoiding excessive alcohol and weight loss
- Screen patients for psoriatic arthritis and metabolic syndrome
- Topical therapy
- Topical steroids and Vitamin D anologues
- Systemic therapy
- Oral systemic therapy