Skin Complications of IBD

After arthritis, skin disorders represent the next most common extraintestinal complication of IBD. These affect about 5% of people with inflammatory bowel disease.



The name literally means “red bumps.” These tender red nodules, which usually appear over the shins or ankles and sometimes on the arms, occur most in people with ulcerative colitis (2%-4%), although they may also affect those with Crohn’s disease of the colon (1%-2%). Women are more commonly affected than men. Erythema nodosum generally appears in conjunction with a flare-up of IBD, but it also may occur just before a flare-up. It tends to improve when the bowel disease is brought under control.


This condition is marked by pus in the skin associated with deep ulcerations. Like erythema nodosum, pyoderma gangrenosum is most often found on the shins or ankles but sometimes occurs on the arms, too. Beginning as small blisters, these lesions eventually join together to form into deep,chronic ulcers. The disorder is somewhat more common among people with ulcerative colitis (5%) than those with Crohn’s disease (1%). Pyoderma gangrenosum often follows a similar course to the pattern of the IBD itself, and may heal as the symptoms of IBD are brought under control. Antibiotics, injections of medications into the ulcers, and topical ointments all may be used as treatments.


A fistula is a small tunnel connecting two parts of the body. An enterocutaneous fistula is an abnormal channel from the intestine to the skin—often from the rectum to the vagina, bladder, or buttocks. It also may be a complication of surgery. This type of fistula may leak pus or fecal matter. Fistulas are more common in Crohn’s disease than in ulcerative colitis, affecting approximately 30% of people with Crohn’s. Treatment depends on the location and severity of fistulas.


Skin tags are fairly common in people with Crohn’s disease. They develop around hemorrhoid swellings in and around the anus. When the swellings go down, the skin around them thickens and forms into small flaps. Fecal matter may attach to skin tags, irritating the skin. Practicing good hygiene will help reduce discomfort and calm the irritation. Surgical removal of skin tags should be avoided because of the risk of damage or scarring the anal sphincter or the anal canal itself.


These are small tears in the lining of the anal canal. They may crack and bleed, causing pain and itchiness. Warm baths and topical ointments may be helpful.


These small mouth ulcers, also known as canker sores, are most often found between the gums and lower lip or along the sides or base of the tongue. They are usually seen during severe flare-ups of IBD and generally subside as the bowel disease comes under control. Medicinal mouthwashes may be helpful, along with a balanced diet and a multivitamin/mineral supplement.



Severe cases of IBD may produce other skin disorders associated with nutritional deficiencies. For example, people who have chronic diarrhea may lose zinc in their stool. This zinc deficiency may lead to acrodermatitis enteropathica, a flaky rash that generally appears on the face, hands, feet, and perineum. Various vitamin deficiencies also may produce skin manifestations such as bleeding or swollen gums and a flaky rash. These problems are less common today because of the increased attention to the importance of good nutrition in chronic illnesses such as IBD.

PYODERMA VEGETANS and VASCULITIS are other rare skin disorders, believed to be due to abnormal immune system activity.

  • Pyoderma vegetans, which affects people with ulcerative colitis, appears as blisters, plaques, or patches around the groin and under the arms. These become darkened areas of skin as they heal.
  • Vasculitis, which means “inflammation of the blood vessels,” is marked by raised reddened areas, sometimes ulcerous.

Treatment of both these disorders centers on treatment of the IBD itself.


This may develop in people who have had Crohn’s disease for many years. It is a blistering condition that appears on the knees, elbows, hands, and feet.

VITILIGO (marked by areas of decreased pigmentation) and PSORIASIS (a scaly, itchy disease) are occasionally linked with IBD, as is CLUBBING (in which the skin beneath the nails becomes thickened). The first two may respond to ultraviolet light therapy and oral medications. There is no treatment for clubbing.


In some cases, a skin disorder is a result not of the IBD itself but rather of the medications used to treat the IBD.

  • Sulfasalazine, for example, may produce an allergy-type skin rash in some people. The reaction is attributed to the sulfa component of this agent. Newer medications—including mesalamine (Asacol®) and olsalazine (Dipentum®)—are similar to sulfasalazine but are manufactured without the sulfa ingredient.
  • Steroids also may cause skin problems when used on a long-term basis. These include stria or stretch marks, thinning of the skin, aggravation of acne, facial puffiness, ankle swelling, and slow wound healing.

For further information, call Crohn's & Colitis Foundation's IBD Help Center: 888.MY.GUT.PAIN (888.694.8872).

The Crohn's & Colitis Foundation provides information for educational purposes only. We encourage you to review this educational material with your health care professional. The Foundation does not provide medical or other health care opinions or services. The inclusion of another organization's resources or referral to another organization does not represent an endorsement of a particular individual, group, company or product.

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Published: May 1, 2012

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