Psoriasis

What is psoriasis?

Psoriasis is an autoimmune skin condition that causes the skin to become red and flaky, and develop a texture that resembles silver scales. You can get psoriasis on any part of your body, but the most commonly affected areas are the scalp, the elbows, knees, and the lower back and tailbone area.

Most people will usually only get psoriasis in small patches. These patches may become itchy, or even painful. However, more severe cases can have the patches expand and spread until they cover large areas of the body.

Who gets psoriasis?

There’s no clear reason why people get psoriasis, but some people might be more at risk than others.^[1] You’re more at risk of developing psoriasis if there’s an issue with your immune system, but it can also be a genetic problem (although it’s not clear why psoriasis runs in families).

You might also be more prone to psoriasis if you’ve injured your skin in any way, if you’ve had a throat infection, or if you’re taking any particular medications such as ibuprofen or ACE inhibitors, which are used to treat high blood pressure.

If you suspect that your psoriasis might be triggered by medication, you should speak to a clinician about it, so that they can factor this into your treatment.

Lifestyle choices can also affect your risk of developing psoriasis. For example, drinking a lot of alcohol, smoking, and high-stress levels can trigger the condition.

How common is psoriasis?

Psoriasis is a fairly common condition that affects around 1-3% of the world’s population.^[2] You can develop it at any point in your life, but it’s most likely to develop between the ages of 20-30 and 50-60. Men and women get it in similar numbers, so sex doesn’t appear to be a risk factor.^[3]

What causes psoriasis?

Psoriasis is caused by your skin cells being replaced more rapidly than normal. There’s no clear reason why the body does this, but it’s believed that your immune system attacks skin cells that are healthy by mistake, and this triggers the symptoms.^[1]

Usually, it takes the body three to four weeks to create new skin cells, and for these skin cells to rise to the top layer of the skin from the bottom. But if you have psoriasis, your immune system isn’t working the way it should, and it causes this almost one-month-long process to take just three to seven days.

Because the skin cells don’t have time to develop properly, they accumulate quickly on the surface. This causes your skin to have a red and flaky appearance, and the silvery scales are a result of the overlaying.

What are the symptoms of psoriasis?

Usually, psoriasis causes dry and red patches of skin that resemble scales and have a silvery colour. But there are different types of psoriasis,^[2] and each will have different symptoms. They include:

• Psoriasis vulgaris, more commonly known as plaque psoriasis. This is the most common form of psoriasis, found in 90% of cases. It’s characterised by the red, flaky, silver scales that are usually found on the scalp, knees, elbows, and lower back, but could appear anywhere.
• Guttate psoriasis, which is more frequently found in children and teenagers. It usually consists of small droplet-shaped spots, rather than the silvery scales you get with plaque psoriasis. These spots can appear all over the body, but usually affect the torso, upper arms, and thighs. Most cases of guttate psoriasis are solved without needing treatment, but some cases are more persistent and need treatment.
• Erythrodermic psoriasis, which is the rarest and most serious form of psoriasis. People suffering from it can have more than 90% of their bodies affected by red, fiery skin that resembles severe sunburn. It can cause body temperature fluctuations, itchiness and a faster heart rate. This form of psoriasis can lead to many complications and requires urgent medical attention.
• Palmoplantar psoriasis, which affects the palms of the hands and soles of the feet, with the affected areas turning a pinkish-yellow colour.
• Inverse psoriasis, which is usually localised in skin folds such as the armpits, groin, under the breasts, genitals and buttocks, and looks like bright red patches with distinctive edges. This form of psoriasis also tends to be resistant to treatments.

• Pustular psoriasis, which is characterised by lesions on the palms of your hands and soles of your feet. These appear as yellow-brown pus-filled bumps in areas affected by psoriasis plaques, or redness and scaling with pus-filled bumps at the tips of the fingers and toes. They can also spread all over your body (in which case it’s called “generalised pustular psoriasis”). If this is the case, you should seek immediate medical attention. Pustular psoriasis can cause chills, fever, nausea, and muscle weakness.

Can psoriasis lead to other problems?

Psoriasis can cause your joints to become painful and tender. This is called psoriatic arthritis and usually needs to be treated by a rheumatologist.^[3] The appearance of psoriasis can sometimes affect peoples’ self-esteem too.

If you’re worried about the physical and mental impact that psoriasis is having on you, you should speak to your clinician, so they can advise you on any additional treatments if required, or refer you to a mental health specialist.