Psoriasis

Your health expert: Dr Anton Alexandroff, Consultant Dermatologist
Content editor review by Pippa Coulter, Freelance Health Editor, February 2023
Next review due February 2026

Psoriasis is a skin condition that typically causes raised patches of red, scaly skin, called plaques. Symptoms tend to come and go over time. There’s no cure for psoriasis. But there are lots of treatments and things you can do to help manage symptoms.

About psoriasis

If you have psoriasis, your skin produces new cells faster than normal. These build up on your skin causing the thick, red, crusty patches associated with psoriasis. Your skin may also become inflamed.

Psoriasis symptoms usually come and go. You’ll have periods when you have no or hardly any symptoms. But there can be other times when you experience a flare-up of symptoms.

It’s thought than between 1 and 3 in every 100 people in the UK have psoriasis. You can develop it at any age. But it’s more likely to begin between the ages of 20 and 30 or between the ages of 50 and 60. Psoriasis affects men and women equally. It isn’t contagious so you can’t catch it or pass it on to anyone else.

Psoriasis causes

It’s not clear exactly why some people develop psoriasis. But genetics is thought to be a major factor. You’re more likely to get it if other people in your family have the condition.

The condition seems to affect how your immune system responds to different factors. These can trigger the onset of psoriasis. They can also cause a flare-up in people who already have the condition.

Trigger factors include:

throat infections
an injury to your skin, including scratches, burns or getting a tattoo or piercing
certain medicines including lithium, some antimalarial drugs, some drugs for high blood pressure and certain antibiotics
sunlight – this usually helps with psoriasis, but in some people it can worsen it
hormonal changes such as puberty, after childbirth and during menopause
stress
smoking
drinking too much alcohol
being obese

Symptoms of psoriasis

Psoriasis causes inflamed patches or areas of skin. It can also affect other areas of your body, including the following.

Your fingernails and toenails may be affected by pitting (tiny holes in your nail). Your nails may also become thickened, discoloured or loosened from the nail bed.
Your joints may be affected, causing pain, swelling and stiffness. This is known as psoriatic arthritis. It tends to affect the joints in your hands, feet, knees and ankles.

There are different types of psoriasis. Your symptoms will depend on the exact type of psoriasis you have.

Plaque psoriasis

This is the most common type of psoriasis. It’s also known as psoriasis vulgaris. With this type, you get thickened, red patches of skin, which may be covered with silver-white scales. Some people have lots of plaques and others only have a few. The plaques can appear anywhere on your body. But they commonly appear on your back, tummy, scalp, knees and elbows. They may:

look pink or red on white skin, and grey on darker skin
range in size from 1 centimetre to several centimetres across
itch and sometimes bleed
develop a crack if they’re on your hands, feet or over a joint such as your elbow or knee
sometimes have a pale ring around the plaque
be very thick on your scalp and look like dandruff
cause some hair loss if they’re on your scalp

Guttate psoriasis

In this type of psoriasis, you may have small, scaly, inflamed spots on your body, arms and legs. They tend to appear over the course of a week. This type tends to affect children, teenagers and young adults, often after they’ve had a throat infection. It usually disappears after 3 to 4 months.

Pustular psoriasis

This type of psoriasis causes small, pus-filled spots (pustules) on your skin. These may just be on the palms of your hands, the tips of your fingers or toes or the soles of your feet.

More rarely, it can be a severe condition where pustules appear over your whole body. This is called generalised pustular psoriasis. It usually affects people who already have plaque psoriasis. This is an emergency as it can be life-threatening and needs immediate hospital treatment.

Flexural psoriasis (inverse psoriasis)

This is a type of psoriasis that causes patches of smooth, red, shiny skin in areas where your skin folds. This might include your armpits, groin and genital area.

Erythrodermic psoriasis

This is a rare form of psoriasis where your skin becomes red and inflamed all over. It can be painful and very itchy. It usually affects people who already have psoriasis, and can come on gradually or suddenly. Erythrodermic psoriasis can be life-threatening, so it’s important to get immediate medical attention.

If you have any of these symptoms, contact your GP. If you have erythrodermic psoriasis or generalised pustular psoriasis, you may feel very unwell with a high temperature and fast heart rate. Seek urgent medical attention if you have symptoms of these types of psoriasis.

Diagnosis of psoriasis

Your GP will usually be able to diagnose psoriasis by asking about your symptoms, your medical and family history, and examining your skin. They’ll consider how the affected areas of skin look, how big they are and where they are on your body. Your doctor will want to know if your symptoms are affecting your normal activities and how it’s making you feel.

Your GP may refer you to a dermatologist if:

there’s any uncertainty about what’s causing your symptoms
your symptoms are particularly severe
a large area of skin is affected

A dermatologist is a doctor who specialises in identifying and treating skin conditions.

If you have signs of psoriatic arthritis such as painful joints, your GP may refer you to see a rheumatologist. This is a doctor who specialises in identifying and treating conditions that affect your joints and muscles.

If you have symptoms of generalised pustular psoriasis or erythrodermic psoriasis, your GP will refer you straight to a specialist. They will carry out further assessment and treatment.

Self-help for psoriasis

There are certain things that can make psoriasis flare up – for example, feeling stressed, drinking alcohol, smoking, and being overweight. You may be able to ease your symptoms by identifying what triggers your psoriasis and avoiding these things. This may include:

managing stress levels
not drinking alcohol to excess
if you smoke, stopping
losing excess weight if you need to

Sunlight can make psoriasis better, so try to spend plenty of time outdoors. Don’t overdo it though – too much sun can trigger a flare up in some people. It can also cause sunburn and increase your risk of developing skin cancer, so it’s important to stay safe in the sun. You should also be careful exposing your skin to the sun if you’re using certain psoriasis medicines, such as tazarotene or acitretin. You may sunburn more easily while taking these medicines.

Psoriasis treatment

There’s no cure for psoriasis. But there are lots of treatments that may help to control your symptoms. You may need to try different ones to find what works best for you. Your GP may be able to prescribe some treatments, but others are only available through referral to a specialist. Which treatments your doctor recommends will depend on the type of psoriasis you have, where it is on your body and how severe it is.

Topical treatments

Topical treatments are products that you apply directly to your skin – for example, creams, lotions and ointments. If you have mild psoriasis or only small areas of skin affected, this may be all you need. Topical treatments for psoriasis include the following.

Emollients. These moisten, soften and soothe your skin. You should apply them regularly and generously, even when your skin appears to be clear. Emollients can sometimes be the only treatment you need. They may also help other psoriasis treatments work better.
Corticosteroid creams. These help to reduce inflammation. You should only use steroid creams for a short time, especially on your face or genitals or if it’s a stronger steroid. You should stop them once your skin is clear or nearly clear.
Vitamins D ointments and lotions. You’ll usually be prescribed these alongside corticosteroid creams. You can also use these preparations on their own, and for longer periods of time than corticosteroid creams.
Calcineurin inhibitors such as tacrolimus and pimecrolimus. These are often used in areas that are difficult to treat such as your face or skin folds. A specialist will usually need to prescribe these.
Salicylic acid-containing products. These can be useful on thick areas of skin, where they help to reduce scaling.
Vitamin A analogues (retinoids) such as tazarotene. These can be useful to treat small patches of mild-to-moderate plaque psoriasis. Your doctor won’t prescribe these if you’re pregnant, breastfeeding or planning to get pregnant because they could harm your baby.
Coal tar ointments and shampoos. These may be an option for psoriasis on your scalp, body or limbs that hasn’t cleared up with other treatments. Older products can smell, and can be messy and stain skin and clothing. Newer, branded products are less likely to have these problems.
Dithranol creams. Your doctor might prescribe this if other treatments haven’t worked. It’s usually only used on tougher skin, like your elbows and knees. You only leave it on for a short time before washing it off. The treatment can stain, so take care when using it.

If topical treatments don’t completely control your symptoms or your psoriasis covers a lot of your body, your GP may refer you to a dermatologist. A dermatologist is a specialist in skin conditions and will be able to discuss additional treatment options.

Light therapy

Your doctor may offer you ultraviolet (UV) light therapy for mild to moderate psoriasis when creams and ointments aren’t enough. This is also called phototherapy. You have light therapy at hospital. You stand in a special unit where you’re exposed to ultraviolet fluorescent lights.

There are two types of light therapy.

Ultraviolet B (UVB) light therapy. This uses a small part of the UVB light naturally found in sunlight. You might have this to treat plaque psoriasis or guttate psoriasis.
Ultraviolet A (UVA) light therapy with psoralen (PUVA). This involves taking a medicine called psoralen before having light therapy. Psoralen makes your skin more sensitive to UVA light.

Light therapy usually involves two or three sessions a week for between 10 and 20 weeks.

Phototherapy is very different from using sunbeds, which aren’t beneficial for psoriasis. With phototherapy, the dose and strength of the ultraviolet light are carefully controlled. Commercial sunbeds don’t filter the type and dose of ultraviolet light you receive. Most commercial sunbeds use a lot of UVA light, which isn’t much benefit to psoriasis on its own.

Tablets and capsules

Several medicines for psoriasis are available in tablet form to be taken by mouth. These include methotrexate, ciclosporin, acitretin and apremilast.

These medicines work by reducing the activity of your immune system or slowing down the production of skin cells. Your doctor may prescribe them if you have severe psoriasis and other treatments aren’t helping. They can be very effective. But they can cause severe side-effects so your doctor will want you to have regular check-ups.

Some of these medicines can be harmful during pregnancy. You may be asked to take precautions not to get pregnant (or to get your partner pregnant). Ask your doctor for more details if you’re considering trying for a baby.

Injections

If your psoriasis is severe and other treatments haven’t helped or aren’t suitable for you, your doctor may suggest a biological medicine. These are given as injections under your skin or into a vein. Biological medicines block chemicals in your body that cause inflammation. Examples include etanercept, infliximab, ustekinumab and ixekizumab.

Living with psoriasis

Having psoriasis can make you feel anxious and depressed, especially if you feel self-conscious about how your skin looks. If you’re feeling like this, speak to your doctor, as they will be able to offer further advice and support. Charities and support groups can also offer useful advice. For more information, see our section: Other helpful websites.

You can’t pass psoriasis onto other people. So there’s no reason why you shouldn’t go swimming, have sex or take part in any of your usual activities. If sex is uncomfortable due to psoriasis in your groin or genital area, using a condom and lubrication may help.

Having psoriasis can increase your risk of heart disease and stroke. Your GP may want to monitor you and assess your risk factors for these conditions. These may include measuring your blood pressure and cholesterol levels. You can reduce your risk by:

following a healthy diet
keeping active
stopping smoking if you smoke
losing weight if you need to
keeping within recommend limits if you drink alcohol

You shouldn’t take creams or gels containing the vitamin A analogue tazarotene if you’re pregnant. This could potentially harm your baby. There are also some psoriasis medicines that you take by mouth that you should avoid when you’re pregnant. If you’re considering trying for a baby, talk to your doctor about your psoriasis treatments. For further information, see our treatment section.

No, tanning sunbeds are not helpful for psoriasis. Ultraviolet (UV) light therapy (phototherapy) prescribed by a dermatologist is tightly controlled, making it safe and effective for psoriasis. Using a commercial sunbed isn’t a safe or effective alternative. For further information about light therapy see our treatment section.

There are likely to be several factors involved. Genetics plays a major part. You may have other people in your family who have psoriasis. Certain factors may trigger psoriasis if you are at risk of developing the condition. These include throat infections, damage to your skin, certain medicines and lifestyle factors. For further information, see our causes section.

Psoriasis causes inflamed patches of skin that may look red or scaly. Exactly how it affects your skin can be different for different types of psoriasis. It can affect your finger and toenails too, causing tiny holes (pitting) or thickening. It can also cause pain, swelling and stiffness in your joints. For further information, see our symptoms section.

There isn’t a cure for psoriasis. But it does tend to come and go over time. You may have periods without any symptoms at all. When your symptoms do flare up, there are things you can do and treatments you can use to help get them under control. There is more information in our self-help and treatment sections.

Psoriasis

About psoriasis

Psoriasis causes

Symptoms of psoriasis

Plaque psoriasis

Guttate psoriasis

Pustular psoriasis

Flexural psoriasis (inverse psoriasis)

Erythrodermic psoriasis

Diagnosis of psoriasis

Self-help for psoriasis

Psoriasis treatment

Topical treatments

Light therapy

Tablets and capsules

Injections

Living with psoriasis

More on this topic

Did our Psoriasis information help you?

Psoriasis

About psoriasis

Psoriasis causes

Symptoms of psoriasis

Plaque psoriasis

Guttate psoriasis

Pustular psoriasis

Flexural psoriasis (inverse psoriasis)

Erythrodermic psoriasis

Diagnosis of psoriasis

Self-help for psoriasis

Psoriasis treatment

Topical treatments

Light therapy

Tablets and capsules

Injections

Living with psoriasis

More on this topic

Corticosteroids

Psoriatic arthritis

Did our Psoriasis information help you?