Are there any foods you should avoid if you have a psoriasis?

There are no known specific foods that trigger psoriasis but many advocate a diet free of inflammatory foods dairy, processed foods, fatty foods, Some avoid nightshades -tomatoes, peppers, eggplants ( potatoes) and gluten, Try a week or 2 off a particular food item to assess the effect. https://www.healthline.com/health/foods-to-prevent-psoriatic-arthritis#antioxidants

Diet not a major factor in Psoriasis activity although most Psoriasis patient are overweight , thus this is important to reduce weight appropriately