What is psoriasis?
Psoriasis is a skin condition which causes patches, or ‘plaques’, of well-defined red, flaky skin sometimes covered with silvery scales. The most common areas are elbows, knees, scalp and lower back, but the rash can appear anywhere on the body.
Psoriasis is a chronic condition that comes and goes in a cycle. Most people will get flare-ups periodically with very mild or no symptoms in between flare-ups. Psoriasis is not contagious so it can't be spread from person to person.
What are the symptoms of psoriasis?
Patches of red or pink skin (sometimes described as ‘salmon pink’)
Thickened skin which forms ‘plaques’
Flaking, dry skin
Silvery scale appearance
Sometimes the rashes are itchy.
Some forms of psoriasis also involve nail changes. Nails may develop small pits, dents or ridges, or become discoloured.
Psoriasis can also affect the joints, with some patients developing joint swelling, stiffness and pains.
Sometimes psoriasis rashes can become infected. If this happens you may develop weeping patches of skin, yellow crust or swelling around the rash.
How common is psoriasis?
Around 1 in 100 people around the world get psoriasis at some point in their life. It can happen at any age, but it's much more common in adults than children. Most people with psoriasis have their first symptom before they're 35.
It's equally common in women and men.
What causes psoriasis?
It’s not known exactly why psoriasis develops, but there are several possible causes.
Every day, you shed old skin cells and replace them with new ones. With psoriasis, your immune system stimulates new skin cells to grow faster than you can shed the old ones. This causes a thick build-up of dead skin cells.
Many people with psoriasis have family members with the condition.
Environment and lifestyle factors
Some psoriasis triggers include:
Bacterial and viral infections
How is psoriasis diagnosed?
Psoriasis can usually be diagnosed by your skin's appearance. Sometimes a doctor might recommend having a sample of your skin taken to be examined in a lab.
How is psoriasis treated?
Topical treatments applied to your skin are the most common treatment.
Emollients (moisturisers) should be applied to your skin regularly. This is particularly important if you're having a psoriasis flare-up, but following a good, consistent routine can help prevent flare-ups too.
If emollients are not helping, other topical treatments can be prescribed by a GP. These include vitamin D analogue creams, steroid creams, coal tar preparations and calcineurin inhibitor creams.
In the case of severe psoriasis, a GP will refer you to a dermatologist. Specialist treatments for psoriasis include phototherapy (light therapy), and medication that can moderate your immune system.
When should I talk to a doctor?
A GP will usually be able to diagnose psoriasis in a clinical examination. If there’s doubt about what it might be, a small skin sample can be taken for analysis.
See a GP if:
Your psoriasis is not improving despite regular use of emollient creams
Your psoriasis becomes infected
Your psoriasis is affecting your daily life or mental health
You have psoriasis and also develop joint swellings or pains
Frequently asked questions
- Reviewed by:
- Dr Rhianna McClymont, Lead GP at Livi