Psoriasis is a chronic inflammatory skin disease where skin cells regenerate too quickly and form thick, red patches of skin with white or silver scales.^[1] A 2017 study found that up to 11% of adults and 1.4% of children worldwide have psoriasis.^[2]

Psoriasis typically looks like elevated lesions that are red, dry, and have silvery scales. They can appear anywhere on the body, such as:^[1]

• Elbows
• Knees
• Scalp
• Face
• Palms
• Feet

The diagnosis is largely clinical, based on the appearance of the rash and associated symptoms. A healthcare professional must first rule out other diseases that may cause similar symptoms. During a visit with a healthcare professional, a clinical history is acquired and a comprehensive skin evaluation is done.^[3]

Treatment is determined by the extent and severity of symptoms. Medical treatments include:

• Topical creams (e.g. steroids and moisturizers)
• Oral or injected medications (e.g. immunosuppressants)
• Phototherapy (exposing skin to different wavelengths of light)

Topical treatments are used for milder cases. If there is no response to topical treatments or for more severe cases, immunosuppressants and/or phototherapy (a treatment that uses ultraviolet light) may be used.^[3]

Dietary supplements are often sought out to relieve symptoms of psoriasis. Supplements with the most evidence include:

• Fish oil
• Vitamin D
• Selenium
• Probiotics

Some studies show that the above supplements are either beneficial or ineffective. More rigorous research is needed before recommendations can be made.^[4]

Observational studies have demonstrated that people with psoriasis consume a lower amount of foods typically found in a Mediterranean diet (e.g., olive oil, fruits, fish, nuts, and whole grains).^[5][6] Research using dietary interventions found that a hypocaloric diet in overweight or obese people with psoriasis or a gluten-free diet in people with a gluten sensitivity shows the most promise for helping reduce symptoms of psoriasis.^[7] It is recommended that changes in diet should be used alongside standard medical treatments.^[7]

There is some weak evidence that saltwater baths combined with phototherapy is effective. However, these findings are inconclusive and further research is required.^[8] There are also some small studies suggesting that meditation can help alleviate some symptoms.^[9]

Psoriasis is thought to be caused by an excessive immune response, which results in an overabundance of skin cells regenerating. The development of psoriasis includes a combination of genetic, environmental, and psychological components.^[3]