Overview
Psoriasis is a chronic autoimmune skin condition that speeds up the skin cell lifecycle. Cells build up rapidly on the surface of the skin, forming scales and red patches that can be itchy and sometimes painful. Psoriasis is a long-term condition that tends to go through cycles, flaring for a few weeks or months, then subsiding. It is not contagious. Beyond the skin, psoriasis is associated with inflammation throughout the body.
Causes and risk factors
The following factors are associated with the development of Psoriasis:
- Autoimmune dysfunction — T-cells attack healthy skin cells
- Genetic predisposition — strongly inherited condition
- Triggers: stress, infections, certain medications
- Skin injury (Koebner phenomenon)
- Smoking
- Excessive alcohol
- Hormonal changes
- Cold, dry weather
- Certain medications: beta-blockers, lithium, antimalarials
Signs and symptoms
Common signs and symptoms of Psoriasis include:
- Red patches of skin covered with silvery scales
- Dry cracked skin that may bleed
- Itching, burning, or soreness
- Thickened, pitted, or ridged nails
- Swollen and stiff joints (psoriatic arthritis)
- Patches typically on knees, elbows, trunk, and scalp
- Severity ranges from minor scaling to major body coverage
- Pustular or guttate forms have different patterns
Diagnosis
Psoriasis is typically diagnosed through a combination of medical history, physical examination, and appropriate investigations such as blood tests, imaging, or specialist review, depending on the specific condition and presentation. Your doctor will consider all relevant symptoms and risk factors before making a diagnosis.
Treatment options
Treatment approaches for Psoriasis may include:
- Topical treatments: corticosteroid creams, vitamin D analogues (calcipotriol)
- Coal tar preparations
- Topical retinoids (tazarotene)
- Phototherapy: narrowband UVB, PUVA
- Systemic medications: methotrexate, ciclosporin, acitretin
- Biologic therapies: TNF inhibitors, IL-17 inhibitors, IL-23 inhibitors
- Moisturisers and emollients
- Avoiding known triggers
Prevention
No known prevention. Managing stress, avoiding known triggers, not smoking, limiting alcohol, and protecting skin from injury may reduce flares.
Complications
If left untreated or poorly managed, Psoriasis can lead to complications including:
Psoriatic arthritis (affects up to 30%), cardiovascular disease, metabolic syndrome, depression, and anxiety.
Sources and references: This article is written in accordance with NHS UK, WHO, and Mayo Clinic clinical guidelines. It is reviewed for accuracy by the SymptomSense content team. ICD-10 code: L40. Last reviewed June 2026.