Psoriasis
Created: 09.01.2025
Updated 22.05.2026
Approved by: Consultant Dermatologist, Dr James Denny
What is Psoriasis?
Psoriasis is a chronic inflammatory skin disease driven by an overactive immune system. It accelerates the life cycle of skin cells, causing them to build up rapidly on the surface of the skin. This results in thickened, scaly plaques.
Approximately 2% of the population is affected. Psoriasis occurs equally in men and women and often develops before the age of 35, although it can begin at any age.
The condition has a strong genetic component. Flare-ups may be triggered by:
- Infections, particularly throat infections
- Stress
- Certain medications
- Skin injury
- Smoking and excess alcohol
Psoriasis is not contagious.
Up to one third of patients may develop psoriatic arthritis, a related inflammatory joint condition that requires early specialist assessment.
What are the symptoms?
Psoriasis typically presents as well-defined, red or pink plaques covered with silvery-white scale.
Common features include:
- Thickened, scaly patches
- Flaking and shedding of scale
- Itching or soreness
- Cracked or bleeding plaques in severe cases
- Nail changes such as pitting or separation
Psoriasis most commonly affects:
- Elbows and knees
- Scalp
- Lower back
- Hands and feet
When it occurs in skin folds, such as the armpits, groin, or under the breasts, it may appear red and smooth without obvious scale. This form is sometimes referred to as inverse psoriasis.
Types of psoriasis
There are several clinical types, including:
- Plaque psoriasis, the most common form
- Guttate psoriasis, often triggered by infection
- Inverse psoriasis affecting skin folds
- Pustular psoriasis
- Erythrodermic psoriasis, a rare and potentially serious form
Severity varies widely. Mild psoriasis may involve small localised patches, while severe psoriasis can affect large areas of the body and significantly impact quality of life.
Psoriatic arthritis
Up to one third of people with psoriasis may develop joint inflammation known as psoriatic arthritis. Symptoms include:
- Joint pain and stiffness
- Swelling of fingers or toes
- Morning stiffness
- Tendon inflammation
Early diagnosis is important to prevent long-term joint damage. Dermatology and rheumatology collaboration is often required.
How is psoriasis diagnosed?
Diagnosis is usually clinical and based on examination of the skin, scalp, and nails. A skin biopsy is rarely required but may be performed if the presentation is atypical.
Assessment also includes evaluating:
- Disease severity
- Impact on daily life
- Joint symptoms
- Associated medical conditions
Specialist dermatology input ensures accurate classification and an individualised management plan.
Treating psoriasis
There is currently no cure, but treating psoriasis effectively can control symptoms and reduce flare-ups. Treatment is tailored according to severity, location, and patient preference.
Topical therapy
For mild psoriasis, topical therapy is usually first-line treatment. This may include:
- Vitamin D analogues
- Topical corticosteroids
- Combination preparations
- Emollients to reduce scale and dryness
Correct and consistent application is essential for effectiveness.
Phototherapy
Ultraviolet light therapy may be recommended when topical treatments are insufficient. Phototherapy reduces inflammation and slows excess skin cell production.
Systemic treatments
For moderate to severe psoriasis, systemic medications may be required. These work throughout the body to control immune overactivity.
Options include:
- Oral immunomodulatory medications
- Injectable therapies
- Biologic treatments targeting specific immune pathways
Biologic therapies have significantly improved outcomes for many patients, often leading to substantial or complete skin clearance.
Associated health considerations
Psoriasis is associated with an increased risk of:
- Cardiovascular disease
- Metabolic syndrome
- Depression and anxiety
- Inflammatory bowel disease
Comprehensive care includes monitoring for these related conditions and supporting overall health.
What is the prognosis?
Psoriasis is a lifelong condition with periods of remission and flare-ups. While it cannot be permanently cured, most patients achieve good control with modern treatments.
Early intervention reduces the risk of complications, including psoriatic arthritis and severe disease progression. Regular follow-up with a dermatologist ensures treatment remains effective and adjusted as needed.
Frequently Asked Questions
Is psoriasis an autoimmune disease?
Psoriasis is an immune-mediated skin disease. The immune system becomes overactive and speeds up the production of skin cells, leading to thick, scaly plaques. It is not contagious and cannot be passed from person to person.
Can mild psoriasis become severe?
Yes. While many people have mild psoriasis that remains stable, flare-ups can occur and the condition may progress. Early and consistent treatment helps reduce the risk of severe psoriasis and long-term complications.
What are the early signs of psoriatic arthritis?
Symptoms include joint pain, stiffness, swelling of fingers or toes, and morning stiffness lasting more than 30 minutes. If you have psoriasis and develop joint symptoms, specialist assessment is important to prevent joint damage.
What is the best treatment for psoriasis?
The best treatment depends on severity and affected areas. Mild psoriasis often responds to topical therapy, while moderate to severe psoriasis may require phototherapy or systemic treatments, including biologic medications. A dermatologist will tailor treatment to your individual needs.
Does psoriasis affect overall health?
Yes. Psoriasis is associated with an increased risk of cardiovascular disease, metabolic syndrome, and mental health concerns. Comprehensive care includes managing both skin symptoms and overall health risk factors.
