What is psoriasis?

Psoriasis occurs on any part of the body including the scalp, hands and feet. There are a number of different types of the disease with the amount of skin affected varying, dependent on severity. Psoriasis may be associated with other inflammatory diseases, including inflammatory bowel disease.

Occurring at any age, psoriasis is more likely to appear at two life stages – these are the twenties to early thirties and between 50 and 60. The condition can wax and wane and may substantially diminish a patient’s quality of life.

How is it diagnosed?

Your GP may diagnose the condition based on the appearance of your skin, although in some cases a skin sample may be taken and sent away for analysis. This allows the exact type of psoriasis to be diagnosed and ensures other conditions are ruled out as well. The plaque type of psoriasis is the most common and presents on the trunk, extremities and the scalp.

What causes psoriasis?

Studies suggest that psoriasis is caused by the triggering of immune cells called T cells, which respond as if they were fighting an infection or healing a wound. This sets off an inflammatory process.

Like other auto-immune conditions, flare ups are often triggered by stress, anxiety and hormonal fluctuations, as well as other life events. There may also be a genetic predisposition, but this is not relevant for all. Environmental triggers do play a part and may include alcohol, medication, stress, smoking, being overweight as well as strep-related throat infections. Managing the triggers relevant to you, through lifestyle changes, may prove valuable.

What else may play a part?

Low levels of the sunshine vitamin, vitamin D, is thought to weaken the body’s ability to keep the skin healthy. Although some vitamin D is obtained via our diets, from foods such as egg yolks, oily fish and fortified spreads, the majority is made by the action of sunlight on our skin. Those with psoriasis have an accumulation of dead cells on the surface of the skin and are more likely to cover it up, potentially reducing the amount of UVB light the skin absorbs. This reduces the amount of vitamin D the skin produces and, in turn, impairs how the skin regulates new cell production. Vitamin D has been found to regulate the immune system, with low levels increasing the susceptibility to auto-immune disease.

Recent research also supports the role the gut, and the many microbes that live there (the gut microbiota), plays in the functioning of our immune function. Gut dysbiosis involves an imbalance in the microbiota which, over time, may have a negative effect on body functions including that of the skin. Interestingly, those with psoriasis appear to have a less diverse mix of gut microbes. Studies which have looked at the use of probiotic supplementation to modify the gut microbiota, look promising.

What are the treatments for psoriasis?

There is no cure for psoriasis, but the good news is that the condition may be managed, although finding the right treatment may take some trial and error. The first treatment you are likely to be offered is a topical one such as a gel, cream or ointment which is applied to the skin. The product chosen will have an active ingredient. One example is a vitamin D based gel or ointment, which works by promoting normal cell growth and skin turnover.

If topical treatments are insufficient or your psoriasis is more severe, then phototherapy, which involves exposing the skin to a specific type of UV light, may be helpful. Other treatments include systemic therapies such as retinoids.

Can diet help psoriasis?

Anecdotal reports suggest eliminating some foods may be useful for some people, however, to date there is limited quality data to support this. If you think this may be relevant to you, keep a detailed food diary and work with a registered dietitian to help you identify possible problem foods.

That said, changes to your diet alone are unlikely to be the single answer to your psoriasis, but may help support first line treatments. For example, adopting a Mediterranean diet has been shown to help reduce inflammatory processes. A Mediterranean diet is characteristically rich in fish, including the omega-3 oily variety, nuts, seeds, wholegrains and vegetables.

There are a number of nutrients which are beneficial for the health of the skin. These include vitamins A, C and D, omega-3 fatty acids and minerals such as zinc and selenium. Studies examining diets rich in these nutrients, or supplemented with them, suggest they may be supportive to other first line treatments.

What can I do to help myself?

If you have psoriasis keeping fit, maintaining a healthy weight and adopting a positive mental outlook as well as eating a balanced diet will help support your management of the condition.

Maintaining regular contact with your healthcare team, such as GP or dermatologist, and taking the treatment as prescribed is important to control flare-ups.

Now read:

Am I getting enough vitamin D?
What is an anti-inflammatory diet?
Eat your way to fabulous skin
How to eat for great skin – dietary fats
How to eat for great skin – digestion

This page was reviewed on 21 May 2025 by Kerry Torrens.

Kerry Torrens BSc. (Hons) PgCert MBANT is a Registered Nutritionist with a post graduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including Good Food.

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