What is psoriasis?

Psoriasis is a long-term inflammatory disease that affects the skin and nails. The skin cells grow too quickly, causing red, scaly lesions that can be painful.

Sometimes a person may have sore and inflamed joints as well. This is known as psoriatic arthritis.

Psoriasis tends to come and go over time. People with psoriasis may need lifelong treatment to keep it under control.

What are the symptoms of psoriasis?

Psoriasis causes different symptoms in different people. Symptoms normally develop before age 45.

The most common symptoms are dry, raised, red patches of skin (plaques) covered with silvery scales. The patches usually appear on the knees, elbow, lower back and scalp, but they can appear anywhere on the body.

Psoriasis can also cause dents and discolouration of the nails.

Some people get small, drop-shaped sores on the chest, arms, legs or scalp. Some people get swollen, painful joints.

The symptoms of some rare types of psoriasis include pus-filled blisters or a red, peeling rash that itches or burns intensely.

Cross section illustration of psoriasis

Close-up of psoriasis on skin

What causes psoriasis?

Although the cause of psoriasis is unknown, it is thought that psoriasis occurs in people who have a genetic tendency for their immune system in their skin to react to certain triggers. These may include infections such as streptococcal tonsillitis, HIV and other viral infections, or by severe stress.

Smoking and excessive alcohol intake may worsen the condition.

Some medications may trigger psoriasis or cause psoriasis to become more severe. These medications include lithium, beta-blockers, anti-malarial medication, and rapid withdrawal of systemic corticosteroids.

How is psoriasis diagnosed?

If you think you have psoriasis, see your doctor. They will probably ask you some questions and examine your affected skin. They may refer you to a dermatologist, or a rheumatologist if your joints are affected.

How is psoriasis treated?

There is no cure for psoriasis but there are many treatments that can help to keep it under control.

Mild psoriasis is usually treated with products applied to the skin. These include:

• moisturisers
• tar preparations
• dithranol
• corticosteroid creams or ointments
• vitamin D preparations

You may also receive ultraviolet light therapy. This can slow down the production of skin cells.

If your psoriasis needs stronger treatment, you may be prescribed oral medicines (tablets or pills) or injected medicines to reduce the immune response. Two new medicines for severe psoriasis are now subsidised for people with psoriasis in Australia, Tremfya and Ilumya.

The best thing you can do to improve the psoriasis is quite smoking and limit how much alcohol you consume.

You can help manage your psoriasis by:

• taking your prescribed treatment regularly to help prevent flare-ups
• reducing stress
• having a healthy lifestyle and eating a healthy diet

What are the complications of psoriasis?

People with severe psoriasis have an increased risk of developing diabetes, cardiovascular disease, arthritis, obesity, some types of cancer, inflammatory bowel disease and other immune‐related disorders, and liver and kidney disease.

The condition can affect the nails and joints, and can seriously affect someone's emotional and social wellbeing. It may affect their ability to work, go to school or participate in physical activities.

Your guide to psoriasis - video