Gastroenterologists Should Be Familiar With Dermatologic Complications of IBD

Gastroenterologists must be aware of the common skin conditions that can arise in patients with inflammatory bowel disease (IBD), said Dr Millie Long at the 2018 AIBD Meeting.

Dr Long, who is an associate professor of medicine in the division of gastroenterology and hepatology at UNC School of Medicine, used a series of case reports to illustrate the different manifestations of dermatologic complications that might be seen in patients with IBD. These included perianal pyoderma gangrenosum, a type of cutaneous ulcer; erythema nodosum, inflammation of the fat layer beneath the skin; anti-tumor necrosis factor (TNF)-induced psoriasis of the scalp; and a case of nonmelanoma skin cancer. While these conditions are all very different, she noted that disease-specific therapy should be used to treat them when they occur secondary to IBD.

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The case of psoriasis was an example of what is paradoxical inflammation, where the condition occurs while the patient is being treated with a biologic that is actually indicated for that condition (in this case, psoriasis). The prevalence of anti-TNF-induced skin lesions has ranged from 2-29%, with an incidence of 5 per 100 person-years. These are not limited to patients with IBD and can occur with other autoimmune-mediated conditions as well. They can arise as early as 1 month into treatment, though they more commonly occur during maintenance therapy.

Skin lesions that arise with anti-TNF use manifest most commonly as psoriasiform eczema or xerosis cutis. The prevalence is similar in men and women as well as smokers and non-smokers. A higher percentage of patients with skin lesions develop antinuclear antibodies, suggesting a link. While studies have looked for a relationship between the occurrence of skin lesions and drug trough levels, this does not appear to be a factor.

The majority of cases of anti-TNF-induced skin lesions can be managed with conservative treatment, Dr Long said. These include topical emollients or steroids with or without systemic therapy. Patients typically improve with continuation on the anti-TNF medication. However, discontinuation of the anti-TNF may be indicated in the following cases:

• The patient could not tolerate the condition due to the location;
• Symptoms include itching or pain;
• Symptoms are recurring; or
• Associated arthralgias occur.

In one cohort of patients who discontinued their anti-TNF medication, the majority had resolution of their symptoms over a median of 3 months. Dr Long noted that changing to treatment with ustekinumab can be very effective for severe cases, with efficacy in up to 100% of patients.

Dr Long also discussed the incidence of nonmelanoma skin cancers (squamous and basal cell carcinoma), which can occur in patients who are immunosuppressed. Treatment with thiopurines seem to drive this risk by increasing photosensitization to UVA light; interestingly, combining these drugs with a biologic attenuates this risk. Recommended management includes local resection of the lesion, regular skin examinations, as well as use of sunscreen and sun-protective clothing.

Immunosuppression is also a risk factor for melanoma, and there is an increased incidence among patients with IBD, though this is much rarer than nonmelanoma skin cancer. For melanoma, the risk is associated with the use of anti-TNF biologics.

Dr Long concluded by noting that, in most cases, patients with skin complications can continue on their IBD treatment, but it is important for gastroenterologists to be familiar enough with dermatologic conditions to know when discontinuing therapy is appropriate.

—Kara Rosania

Reference:

Long M. Diagnosis and treatment of dermatologic complications. Presented at: Advances in Inflammatory Bowel Diseases; December 13-15, 2018; Orlando, FL. https://www.consultant360.com/meetings/aibd.