Psoriasis is a chronic inflammatory skin disease caused by overproduction of skin cells. It most commonly manifests itself as plaque psoriasis, in which raised red patches form on the knees, elbows, scalp and lower back. These patches are often itchy and painful, and in some cases can crack and bleed.
The bad news is that there is no cure for psoriasis. The good news is that psoriasis can be successfully managed with the right treatments.
What types of psoriasis are there?
There are several different types of psoriasis, varying in severity. Most people will only suffer from one type of psoriasis, however it is possible to have more than one in combination, or for your current type of psoriasis to develop into something more serious.
Plaque psoriasis accounts for 90% of psoriasis cases and is recognisable by its distinctive plaques - areas of raised red skin with silvery-white, rough scales. One variation of plaque psoriasis is scalp psoriasis, which resembles severe dandruff and can occur in isolation, or in combination with psoriasis on other parts of the body.
Flexural (or inverse)
This type of psoriasis occurs in the creases of the skin (groin, armpits, any skin folds). It presents with large shiny red patches (easily distinguished from plaques), that are itchy or uncomfortable. It is possible to have flexural psoriasis on certain parts of your body, and plaque psoriasis on others. Flexural psoriasis is often made worse by friction and sweating.
Guttate psoriasis is most common in children and teenagers, and is recognisable by its small, red, drop-shaped sores, that appear on the chest, arms, legs and scalp. Guttate psoriasis will often heal on its own after a few weeks, but in some cases can develop into plaque psoriasis.
Erythrodermic psoriasis is a rare and severe form of psoriasis, in which the entire body is covered in sore, red, flaking skin. This form of psoriasis is dangerous as it can lead to infection, dehydration, heart failure, hypothermia and malnutrition. Erythrodermic psoriasis must be treated in a hospital.
Though psoriatic arthritis is not a skin condition, it usually occurs in those with skin psoriasis - for every 10 sufferers of psoriasis, one will develop this condition as well. Psoriatic arthritis is characterised by pain, swelling and stiffness in the joints of the body (commonly the hands, feet, knees, neck, spine and elbows).
What causes psoriasis?
Psoriasis is a fairly common condition that affects around 2% of the UK population. It is thought that psoriasis is caused by an immune disorder, which causes your body’s infection-fighting T-cells to mistakenly attack healthy skin cells and break them down. In response to this, your skin produces more cells, which continue to be attacked by the T-cells - this leads to a build-up of layers of skin.
No one is sure quite why this immune disorder occurs, however there is evidence to suggest that psoriasis is a genetic disorder - about a third of sufferers have a close family member who also has psoriasis.
Though psoriasis is caused by a problem in your immune system, it can be triggered and made worse by certain factors, as listed below.
Smoking and drinking excessive amounts of alcohol are two things that can trigger a flare-up of psoriasis. There is even some evidence to suggest that smoking can actually cause psoriasis. Alcohol can also lead to serious side effects for psoriasis patients who are being treated with methotrexate.
Injury to your skin (including cuts, scrapes, insect bites and sunburn) can trigger psoriasis, in what is known as the Koebner response. Infection of the throat, ear, tonsils or respiratory system can lead to a flare-up, while hormonal changes such as puberty or the menopause can also exacerbate the condition. Emotional stress is also known to worsen psoriasis.
There are several medicines that are known to trigger psoriasis. These include:
- Lithium, used to treat bipolar disorder and other psychological conditions
- Anti-malarials such as chloroquine
- The high blood pressure medicine Inderal
- Anti-inflammatories such as ibuprofen
What are the symptoms of psoriasis?
The symptoms of psoriasis depend largely upon what type, or types, you are suffering from. However, the most common kind - plaque psoriasis - is generally recognised by:
- raised, red patches of skin that are itchy and sore
- silvery-white rough-feeling scales
- flaking of the scalp
- cracked or bleeding skin around the joints
Another symptom of psoriasis can be cracked, loosened or crumbling nails. If you have developed any areas of sore red skin that are not healing on their own, you should seek medical advice.
What are the treatments for psoriasis?
There is no cure for psoriasis, but there are many treatment options available to help you manage your symptoms on a day-to-day basis. Treatment for psoriasis will vary depending on the severity of the condition, but it usually begins with topical creams or ointments, such as:
- corticosteroids (e.g. Betnovate and hydrocortisone)
- vitamin D analogues (e.g. Dovonex)
- coal tar solutions
- dithranol (e.g. Dithrocream)
It is also recommended that moisturisers and emollients are used on a daily basis to help keep the skin lubricated.
Other treatments include phototherapy, in which ultraviolet light (UVA or UVB, depending on the severity of the condition) is shone on the affected areas, and - for very serious psoriasis - systemic treatments such as methotrexate. For more information on treatment options, visit the NHS website or speak to your doctor.