Skin, hair & nailsAutoimmune/inflammatoryICD-10 L40
Psoriasis
An immune-mediated condition in which skin cells multiply too quickly, forming red, raised, scaly plaques — typically on elbows, knees and scalp. About a third develop psoriatic arthritis.
Condition-specific references are below. Individual claims and this page have not been clinically reviewed. Read about this content.
Causes
- IL-23/IL-17 immune pathway activation in genetically predisposed people
Risk factors
- Family history
- Streptococcal throat infection (guttate)
- Smoking, alcohol, obesity
- Stress
- Some medicines (lithium, beta-blockers)
Symptoms
- Red plaques with silvery scale
- Itching or soreness
- Nail pitting and lifting
- Joint pain and swelling (psoriatic arthritis)
Diagnosis — tests and examinations
- Clinical diagnosis; biopsy occasionally
Treatment
Medicines and medical treatment
- Topical steroids and vitamin D analogues
- Phototherapy (narrowband UVB)
- Methotrexate, ciclosporin, acitretin, apremilast, deucravacitinib
- Biologics (anti-TNF, IL-17, IL-23 inhibitors)
Self-care, home remedies and lifestyle
- Emollients
- Stop smoking, limit alcohol, weight loss
- Sensible sun exposure
Possible complications
- Psoriatic arthritis
- Cardiovascular and metabolic disease
- Depression
Prevention
- Healthy lifestyle reduces flares
Outlook
Chronic but very well controlled with modern treatments.
When to see a doctor
See a doctor for widespread plaques or joint pain.
Sources and further reading
These sources cover this condition. They have not been checked against every statement on this page.
Related conditions
Educational overview, not medical advice. Treatment varies by person and location. Consult a qualified health professional for diagnosis or care. Read our content and model notes and privacy information.