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HealthInfo Waitaha Canterbury

Overview of psoriasis

Tirohanga whānui ki te mate tongatonga uri

Psoriasis elbowPsoriasis is a long-term (chronic), common skin condition that can come and go throughout your lifetime. It can also affect your joints and nails.

It's not infectious, meaning you cannot catch it from other people.

Skin cells are usually replaced every 21 to 28 days. Your body makes new skin cells just under the surface to replace the old skin cells that are dropped off (shed). With psoriasis you make new skin much faster – in only a few days. This causes your skin to get thicker in places, forming rough, red areas and often silvery scales known as plaques.

Causes of psoriasis

Health professionals do not fully understand what causes psoriasis but they believe it's related to a problem with your immune system. An overactive immune system can cause rapid growth of skin cells.

Genetics also appear to play a part in causing psoriasis because the condition can run in families, though some people with psoriasis have no family history. Psoriasis can appear at any age and affects men and women equally.

Certain things can trigger psoriasis or cause a flare-up. These include, stress, anxiety, some skin and throat infections, smoking, excessive alcohol intake and certain medicines.

Symptoms of psoriasis

The severity of psoriasis varies – some people have minimal effects and for others it severely impacts their lives.

Symptoms include:

Read more about different patterns of psoriasis and how they are recognised.

Some people with psoriasis will develop joint problems. This is called psoriatic arthritis.

Diagnosing psoriasis

Usually, your GP diagnoses psoriasis based on the appearance of your skin. They will ask you about which body areas are affected, how it impacts your day-to-day life and if you have any joint pain. They will examine your skin, scalp and nails.

Occasionally you'll need to have a biopsy. This is when a small sample of skin is taken and examined under a microscope.

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On the next page: Self-care with psoriasis

Written by HealthInfo clinical advisers. Last reviewed August 2021.


Page reference: 317067

Review key: HIPSO-20776