What is Psoriasis?

Every human being creates and sheds skin cells every day - it’s part of the skin’s constant replacement process.

In someone without psoriasis, skin cells take 21-28 days to be replaced. When a person has psoriasis, this process speeds up, taking just a few days. So, when you have psoriasis, your skin cells build up on the surface, creating hard plaques and flaky areas. Psoriasis is seen in the skin and sometimes joints, but is actually an immune condition.

So what is it?

Anyone can have psoriasis at any point in their life, and one study estimates that around 1.4% of all people between the ages of 10 and 19 have it, and around 2-3% of the overall UK population is currently affected.

That means that, although you might feel like the only person in the world with psoriasis, we think around 1.8 million people have it in the UK alone! It’s important to remember that psoriasis isn’t contagious- it can’t be caught from someone else, and it can’t be transferred from one part of the body to another.

Modern-day research has discovered that psoriasis is caused by certain changes in the immune system. ‘T Cells’ are immune cells that cause inflammation, normally to heal wounds or fight infection. In people with psoriasis, something triggers these cells to become overactive, leading to the rapid growth of skin cells - a bit like when you hurt yourself and cells rush to the surface to form a scab.

It’s not yet known exactly what triggers these changes. Some people have a family history of psoriasis, but this doesn’t always mean that they will inherit it, and some people with no family history at all can also develop psoriasis. In all types of psoriasis, common triggers may be puberty, skin injuries, emotional stress or certain medicines (e.g. anti-malaria tablets).

Guttate psoriasis is one type which is commonly triggered by a throat infection. Smoking and too much alcohol can make psoriasis worse and trigger new episodes.

Psoriasis cannot be cured, but there are lots of treatments available to manage the condition. Moisturising is an important part of treating psoriasis too. Visit our Mythbuster to get the quick lowdown on what is and isn't true about psoriasis.

For further information on psoriasis take a look at our main website. For or for a list of resources used in the production of this information resource, please contact the Psoriasis Association.

April 2016 (Review: March 2018)

Plaque Psoriasis

Most people with psoriasis have Plaque Psoriasis.

This appears as distinctive raised patches, covered with silvery white scales, known as plaques. On Caucasian skin, areas of psoriasis can look very red, whereas patches on darker skin tones can look much darker than the rest of the skin.

The plaques can vary in size from very small to very large, and are well-defined from the surrounding skin - if you close your eyes and run your hand over the area, you can clearly feel where the plaque starts. They often appear on the knees, elbows and scalp, although can appear anywhere on the body. The build up of scales is simply the skin waiting to be shed, and this can be anything from very fine to very thick and prone to cracking.

You can find further information about plaque psoriasis on our main website.

Erythrodermic psoriasis is a very rare form of the condition, which occurs when a person's psoriasis becomes 'unstable', covers all or most of the skin, and makes the individual feel very unwell.

If you're worried you or someone else may have erythrodermic psoriasis, it is important you visit a doctor immediately. If you'd like more information on erythrodermic psoriasis, please contact the Psoriasis Association.

Guttate Psoriasis

Guttate Psoriasis occurs most often in children and young people, and is usually triggered by a throat infection.

It may sometimes be referred to as ‘raindrop’ psoriasis, as the very small spots look like drops across the body. These are often all over the torso, and sometimes on the arms and legs. It is widespread, but does tend to clear up after a few weeks or months.

After this, some people will never experience another attack, although others might continue to get them whenever they develop a throat infection. In this case, it’s important to make a GP appointment whenever you feel a sore throat coming on, as getting antibiotics early could stop the psoriasis from getting too bad.

Some people with guttate psoriasis go on to develop another form of psoriasis, such as plaque psoriasis, later in life.

You can find more information about guttate psoriasis on our main website.

Scalp Psoriasis

The scalp is the most common body site to be affected by psoriasis in teenagers and young people.

It is often quite similar to the plaque psoriasis on other areas of the body, but occurring in the hair, around the hairline and ears, and down the neck. This can be quite itchy, and also cause flakes to fall into the hair and onto clothes, which some people can find a bit embarrassing. Many people find that wearing a lighter-coloured top hides the flakes better than darker colours.

As with other types of psoriasis, moisturising is important, and - although this can be messy on the scalp - it does help the skin to feel less itchy and irritated, and to raise plaques.

Feeling self-conscious about scalp psoriasis can stop some people from going to the hairdressers, and it is often thought that people with scalp psoriasis can’t dye their hair or have other treatments. Not always true! A reputable hairdresser will know about the condition and how to work around it, and having your hair done can work wonders for your self esteem! Go to the Body Image section for more info.

You can find more information about scalp psoriasis on our main website.

Psoriasis in Sensitive Areas

The skin on some areas of the body is more sensitive than others, and psoriasis in these areas might look a bit different and also need to be treated slightly differently.

Psoriasis in skin folds (known as ‘flexures’), such as in the armpits, groin or under the breasts can look bright red on Caucasian skin, or be an area of darker pigmentation on darker skin tones. Psoriasis in these areas is also usually shiny rather than thick and flaky. This type of psoriasis can be quite sore or itchy, and made worse by tight clothing, soaps and deodorants. Try using deodorants for sensitive skin, or, if you’re not going out and your skin is inflamed, give yourself a break and don’t wear any. Body sprays and perfumes can be sprayed onto clothes, or areas not affected by psoriasis.

Areas where the affected skin is covered by other skin - or the genitals, which are covered by skin and clothing - tend to absorb more of an active treatment. This means that steroids, for example, become stronger when used in a sensitive area. This may sound like a good thing, but it doesn't necessarily mean they'll work better, and could end up damaging your skin. Because of this, you might be given a different treatment to use on psoriasis in sensitive areas than on other parts of your body. You should always check with a doctor or pharmacist before using a treatment prescribed for another part of your body on a sensitive area.

Although it’s fairly rare to get psoriasis on the face, it does sometimes happen, and this is also a sensitive area where some treatments may be more suitable than others.

You can find out more information about psoriasis in sensitive areas on our main website.

Having psoriasis in these areas can make you feel embarrassed, anxious and lacking in self-confidence. These feelings can then start to impact on your social life and relationships. For more help in these areas, please go to the Body Image and Relationships sections.

Psoriasis on the Hands and Feet

Plaque psoriasis may appear on the tops of hands and feet, and this is likely to be treated in the same way as the rest of your body.

However, some care may need to be taken if you are prescribed a steroid cream, and then regularly cover your psoriasis with gloves or socks. This covering can make the skin absorb the steroid more effectively, making it stronger. This may sound like a good thing, but it doesn't necessarily mean the treatment will work better, and it could end up damaging your skin. You should always read the patient information leaflet enclosed with your treatment, and use it as directed.

Nail psoriasis involves changes to the nails themselves - such as pitting, thickening, crumbling, or lifting off the nail bed. It’s possible to have psoriasis on just the nails, and nowhere else. Again, this is another area where the treatment you use for the psoriasis on other parts of your body might not be suitable, so you may be prescribed something different.

Palmoplantar Pustulosis (PPP) is a type of psoriasis that occurs on the palms of the hands and soles of the feet. It tends to occur in adults and is generally quite rare in younger people. The skin on the palms and soles is usually very red or dark with painful cracks and spots filled with yellow pus (pustules). These spots are sterile, and therefore not contagious or infectious. Scientists have found an association between smoking and PPP, although they are still not sure exactly how and why smoking triggers this particular condition. There’s a good excuse not to start, or to try and give up! Pustular psoriasis can sometimes occur across other areas of the body, visit our main website for more information.

Psoriaisis on the hands and feet can sometimes cause problems with work or employment, please contact the Psoriasis Association for more information on this issue.

Psoriatic Arthritis

Psoriatic Arthritis (or PsA for short) is a form of arthritis associated with psoriasis.

Psoriatic Arthritis is an inflammatory joint condition, which means it can cause swelling and inflammation in joints and tendons, as well as stiffness, pain and lack of movement. People with PsA often have nail psoriasis and tend to get arthritis in the joints of the fingers and toes. However, PsA can still occur in other joints. The symptoms can come and go, like psoriasis, and be worse at certain times and better at others.

Although Psoriatic Arthritis is associated with psoriasis, you don’t necessarily need to have psoriasis to get it. In most cases, people do have psoriasis before developing PsA, but sometimes people can get PsA first and psoriasis after, or never get any skin symptoms at all. Similarly, many people have psoriasis and never develop PsA.

It can be quite difficult to diagnose Psoriatic Arthritis; there’s no specific test, so doctors have to take a range of information including family history, symptoms, and the ruling out of other conditions into account. If your doctor thinks you might have PsA, you will be referred to a Rheumatologist for an official diagnosis, and for treatment. There are a number of treatments for PsA, depending on the joints affected and how severe it is. Treatment might include a mixture of anti-inflammatory painkillers, physiotherapy, steroid injections, or tablets or injections of stronger medicines.

You can find out more information on psoriatic arthritis on our main website.

For a list of resources used in the production of this information resource, please contact the Psoriasis Association. November 2017 (Review: March 2020)

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