Pyoderma gangrenosum: From bite to ulcer

Our 36-year-old daughter-in-law is suffering from very painful pyoderma gangrenosum. Her latest outbreak followed a mosquito bite in September, and she is being treated as an outpatient. She also suffers from ulcerative colitis. Is pyoderma linked to colitis? Are there any support organisations?

Dr Fred Kavalier answers your health question:

No one knows the cause of pyoderma gangrenosum. It causes painful skin ulcers, usually on the legs, occasionally on the hands. The ulcers can form after an insect bite or some other minor skin irritation, but they can also just appear for no apparent reason. The worst symptom is pain, which can require very strong painkillers, including morphine. Because the cause of pyoderma is unknown, it is very difficult to treat. Sometimes steroids are used, or strong drugs to suppress the immune system. Although the ulcers look like they are caused by an infection, they don't respond to antibiotics. Nothing seems to work very well. I am not surprised that your daughter-in-law also has ulcerative colitis, as the two conditions are often linked (though, most people with ulcerative colitis don't get pyoderma gangrenosum). I don't think there are any pyoderma gangrenosum support groups, but the National Association for Colitis and Crohn's Disease (NACC) provides information and support for people with ulcerative colitis: 0845 130 2233;

Please mail your questions for Dr Fred to He regrets that he is unable to respond personally to questions