Complications of Crohn's disease outside the digestive tract

Sometimes complications of Crohn's disease can develop outside the digestive tract in other parts of the body (systemic symptoms), including the eyes, liver, blood, and bones. These systemic symptoms suggest that the immune system is involved in Crohn's disease. Complications can include:¹

• Joint problems, which occur in 5% to 20% of people with Crohn's disease. Some people develop colitis-related arthritis, which may resemble rheumatoid arthritis.
• Eye problems, which happen in up to 11% of people with Crohn's disease. These can include ulcers on the cornea, inflammation of the iris and blood vessels (uveitis), and inflammation of the white part of the eyes (sclera).
• Skin conditions, which happen in about 10% to 20% of people. Examples include mouth ulcers and pyoderma gangrenosum, which is an eruption of painful, spreading ulcers that usually occur on the legs. The ulcers may be blue in the center with red edges. Mouth ulcers are more common than pyoderma gangrenosum, which is fairly rare.
• Disorders of the liver and gallbladder, which affect 10% to 35% of people. These can include gallstones, cirrhosis of the liver, bile duct inflammation and scarring (sclerosing cholangitis) or, rarely, bile duct cancer.
• Growth problems in children. Affected children may not grow as quickly or as tall as their peers. Children with Crohn's disease need attention to their diet to ensure that they get enough nutrients.
• Problems with blood clots in the legs or other areas of the body.
• Low bone mass. This happens in 3% to 30% of people with Crohn's disease. The risk is greater for people who take corticosteroid medicines. It can lead to broken bones and, later, osteoporosis. More than half of people who take steroids for the long term get osteoporosis.
• Kidney stones.

Citations

1. Friedman S, Lichtenstein GR (2006). Crohn's disease. In MM Wolfe et al., eds., Therapy of Digestive Disorders, 2nd ed., pp. 785–801. Philadelphia: Saunders Elsevier.