Some people find that spices and condiments are the worst things they can eat for their psoriasis. Condiments like ketchup, mayo, Tabasco sauce, vinegar and Worcestershire sauce and spices like cinnamon, curry, pimento and paprika may all cause inflammation.
If you suspect a particular food might be triggering your psoriasis, try eliminating it from your diet and watch for changes in your skin. Additionally, keep an eye on your weight. "We now know that weight gain increases the severity of psoriasis and the risk of incident psoriasis," says Dr. Delphine Lee, a dermatologist at Providence Saint John's Health Center in Santa Monica, California. "Scientists have studied the effect of weight reduction on the severity of psoriasis in obese patients with psoriasis and found that overweight patients with psoriasis on a diet that restricted calories for eight weeks to induce weight loss followed by eight weeks of reintroduction of normal food intake, showed a trend in favor of improving their psoriasis area and severity index after 16 weeks."
As with any major dietary changes, make sure you talk to your doctor first.