Psoriasis

Psoriasis is a skin condition that causes red, flaky, crusty patches of skin, and these patches are covered with silvery scales.

It can appear on any part of the body, but you'll often find it on the elbows, knees, scalp and lower back.

Psoriasis shows up as patches of skin that are dry, red and covered in silver scales. Some people also find the patches itchy or sore.

The condition can come and go in cycles. You might have symptoms for a few weeks or months, and then they ease or stop altogether.

Psoriasis comes in several different types. Most people have only 1 type at a time, though 2 different types can happen together. Sometimes one type changes into another, or becomes more severe.

Plaque psoriasis is the most common type of psoriasis. It causes patches of dry, red skin, called plaques, which are covered in silver scales.

You'll usually notice the symptoms on your elbows, knees, scalp and lower back, but they can show up anywhere on your body.

The plaques can be itchy, sore or both. In severe cases, the skin may crack and bleed.

Scalp psoriasis can affect just a few parts of your scalp, or the whole of it. You'll see red patches of skin covered in thick silvery-white scales, and they can be itchy. In severe cases, scalp psoriasis can cause hair loss, but this is usually temporary.

Psoriasis can sometimes affect the nails. When it does, the nails may:

• develop tiny dents or pits
• become discoloured
• grow abnormally
• separate from your nail bed
• crumble, in severe cases

Guttate psoriasis causes small, drop-shaped sores on your chest, arms, legs and scalp. In some people it clears up completely after a few weeks. Others go on to develop plaque psoriasis.

This type of psoriasis sometimes appears after a streptococcal throat infection. It's more common among children and teenagers.

Inverse psoriasis affects the folds and creases of your skin, such as the armpits, the groin, between the buttocks and under the breasts. It can cause large, smooth red patches in some or all of these areas.

Friction and sweating make inverse psoriasis worse. This means it can be more uncomfortable in hot weather.

Erythrodermic psoriasis is a rare type of psoriasis. It affects nearly all the skin on the body, and it can cause severe itching or burning.

Pustular psoriasis is a rarer type of psoriasis. It causes pus-filled blisters, which doctors call pustules. There are different types of pustular psoriasis, and each one affects different parts of the body.

Generalised pustular psoriasis, also called von Zumbusch psoriasis, causes pustules over a wide area of skin, and they develop very quickly.

The pus is made up of white blood cells. It isn't a sign of infection. The pustules may come back in cycles, every few days or every few weeks. When a cycle starts, you may get fever, chills, weight loss and fatigue.

Palmoplantar pustular psoriasis causes pustules to form on the palms of your hands and the soles of your feet. Over time, the pustules turn into round, brown, scaly spots, and these then peel off.

New pustules may come back every few days or every few weeks.

Acropustulosis is a form of psoriasis that causes pustules on your fingers and toes. The pustules burst, and they leave bright red areas behind that may ooze or turn scaly. Over time these can change the shape of the nails, and the changes can be painful.

You have psoriasis and:

• your skin quickly turns red and you develop white, pus-filled bumps that join together (redness may be harder to see on brown or black skin)
• your psoriasis patches on your feet turn yellow-brown and are filled with pus
• your fingers and toes have red, scaly, pus-filled bumps on the tips (redness may be harder to see on brown or black skin)

These can be signs of a more serious condition or an infection.

You may also have other symptoms, such as your heart beating fast, a high temperature, or feeling hot, cold or shivery.

See a doctor if you have:

• symptoms of psoriasis
• psoriasis and your treatment isn't working or is giving you side effects
• psoriasis and also have pain, stiffness and swelling in your joints that keeps coming back

Your doctor will look at your skin to check whether you have psoriasis. Sometimes you may also need a biopsy, which helps find the exact cause of your symptoms.

If your symptoms are severe, or your doctor isn't sure what's causing them, you may be referred to a dermatologist (a specialist in skin conditions). And if your doctor thinks you have psoriatic arthritis, you may be referred to a rheumatologist (a specialist in joint conditions).

How psoriasis is treated depends on where the symptoms are and how severe they are.

Many treatments are available, but it may take time to find the best one for you. Often, different types of treatment are used at the same time. Speak to your doctor if you feel your treatments aren't working or if you have any side effects.

Topical treatments are usually the first thing doctors try for mild to moderate psoriasis. These are creams and ointments that you put on the affected areas of skin.

For some people, topical treatments are all they need to keep psoriasis under control. But they don't work straight away, and it may take up to 6 weeks before you notice an effect.

If you have scalp psoriasis, you may need a shampoo and an ointment used together.

Emollients are moisturising treatments that you apply directly to your skin. If you have mild psoriasis, they may be one of the first treatments your doctor suggests.

They help to reduce itching and scaling. Some topical treatments may also work better when your skin is moisturised.

There are many different types of emollients. You can buy them over the counter from a pharmacy, or your doctor can prescribe them.

Doctors use steroid creams or ointments (corticosteroids) to treat mild to moderate psoriasis. They can help bring down the inflammation and ease the itching.

Doctors may prescribe vitamin D analogue creams for psoriasis, either together with steroid creams or in their place. These creams slow down the production of skin cells. They also reduce inflammation.

Calcineurin inhibitors, such as tacrolimus and pimecrolimus, come as ointments or creams. They lower the activity of the immune system and ease inflammation.

Doctors sometimes use them for psoriasis in sensitive areas like the scalp, genitals and folds of the skin, when steroid creams don't help.

Coal tar is a thick, heavy oil used in the treatment of psoriasis. Nobody knows exactly how it works, but it can reduce scales, inflammation and itchiness. Doctors may suggest it if other topical treatments aren't effective.

It has a strong smell, and it can stain your clothes and bedding. You can use coal tar together with phototherapy.

Dithranol is a treatment for psoriasis that can stop the skin from making new skin cells, and it has few side effects. Doctors usually use it for a short time only, and under hospital supervision.

You put dithranol on your skin and leave it there for 10 to 60 minutes, then wash it off.

It can also be used together with phototherapy.

Phototherapy treats psoriasis with natural and artificial light. The artificial kind can be given in hospitals and some specialist centres, usually under the care of a dermatologist. These treatments aren't the same as using a sunbed.

Ultraviolet B (UVB) phototherapy for psoriasis uses a kind of light that human eyes can't see. The light slows down the production of skin cells. It works well for some types of psoriasis that don't respond to creams and other treatments applied to the skin.

Each session takes only a few minutes. But you may need to go to hospital 2 or 3 times a week for 6 to 8 weeks.

With psoralen plus ultraviolet A (PUVA) treatment, you're given a tablet containing psoralens. Psoralen can also be applied directly to the skin. Either way, it makes your skin more sensitive to light.

Your skin is then exposed to a wavelength of light called ultraviolet A (UVA). This light goes deeper into your skin than ultraviolet B light does.

Doctors may use this treatment if you have severe psoriasis that hasn't responded to other treatment.

If your psoriasis is severe, or other treatments haven't worked, a specialist may prescribe systemic treatments. These are treatments that work through the whole body.

They can have serious side effects. Talk to your doctor about your treatment options and any risks that come with them.

There are 2 main types of systemic treatment, called non-biological and biological.

Non-biological treatments for psoriasis come as tablets or capsules. They include:

• methotrexate, which slows down the production of skin cells and reduces inflammation
• ciclosporin, which suppresses your immune system (it is an immunosuppressant)
• acitretin, which reduces the production of skin cells

Biological treatments for psoriasis are given as injections. They reduce inflammation by targeting overactive cells in your immune system.

Biological treatments include:

• etanercept
• adalimumab
• infliximab
• ustekinumab

People with psoriasis make more skin cells than usual. Skin cells are normally made and replaced every 3 to 4 weeks, but when you have psoriasis the same process takes only about 3 to 7 days. The cells build up, and that build-up causes the symptoms of psoriasis.

Nobody knows exactly why this happens, but it may be a problem in the immune system. The immune system is your body's defence against disease and infection. In people with psoriasis, it attacks healthy skin cells by mistake, and that makes the skin produce new cells faster than usual.

Psoriasis also runs in families, so you may be more likely to get it if a family member has it.

It isn't contagious. You can't catch it from another person, and you can't pass it on to anyone.

Psoriasis symptoms often start or get worse because of a particular event. This is called a trigger. If you know your triggers, you may be able to avoid a flare-up.

Common psoriasis triggers include:

• an injury to your skin, like a cut, insect bite or sunburn
• drinking a lot of alcohol
• smoking
• stress
• hormonal changes, particularly in women (for example, during the menopause)
• certain medicines, like lithium, some antimalarial medicines, anti-inflammatory medicines including ibuprofen, and ACE inhibitors (used to treat high blood pressure)
• other immune disorders, like HIV

Psoriasis is a common skin condition, and it can start at any age. Men and women are affected equally.

How severe it is differs from one person to the next. Some people have only mild symptoms, but for others psoriasis can have a major impact on their quality of life.

Some people with psoriasis go on to develop psoriatic arthritis. It's a type of arthritis that affects the joints, and it can leave them swollen, stiff and painful.

Psoriasis can also take a toll on how you feel about yourself. Some people with the condition have low self-esteem or anxiety, and sometimes this leads to depression.

Your doctor or dermatologist will understand the psychological and emotional impact of psoriasis. Talk to them about your concerns or anxieties.

• keep using your treatments as prescribed, even when your symptoms get better, because this helps prevent flare-ups
• talk to your doctor or care team if you have questions about your treatments, or if you notice any side effects
• try to keep up healthy habits, such as regular activity and healthy eating
• try to cut down on stress where you can
• see if there's a support group near you, as it can give you more advice on living with psoriasis