HealthInfo Aoraki South Canterbury
Overview of psoriasis
Tirohanga whānui ki te mate tongatonga uri
Psoriasis 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:
- patches of rough, red skin and silvery white scales called plaques
- itchy skin – can be mild or severe
- scalp, elbows and knees are the most commonly affected sites
- fingernails can be affected, causing the nail to lift away from the finger – this can be painful
- mental health issues – while psoriasis is a skin condition it can also affect people psychologically. Having psoriasis can be very challenging and can increase your risk of anxiety and depression.
Read more about different patterns of psoriasis and how they are recognised.
Some people with psoriasis will develop joint problems. This is called rheumatoid 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.
HealthInfo recommends the following pages
- Patient.info – Psoriasis
This page answers questions such as how common is psoriasis, who gets it and what is the prognosis?
On the next page: Self-care with psoriasis
Written by HealthInfo clinical advisers. Last reviewed August 2021.
SourcesReview key: HIPSO-20776
