Shingles during the course of treatment with 6-mercaptopurine for inflammatory bowel disease

Our aim was to study the frequency, severity, and outcome of patients with Crohn's disease and ulcerative colitis treated with 6-mercaptopurine (6MP) who developed shingles during treatment, and to recommend management. While varicella can be severe in young people immunocompromised by steroids, the incidence of herpes zoster in older people with inflammatory bowel disease (IBD) and whether its severity is influenced by 6MP and azathioprine are unknown.

Data were collected from our IBD Center on 550 patients with IBD to identify those who developed shingles while on 6MP, its severity, the dose and duration of 6MP, and the management of the 6MP.

Twelve of 550 patients with IBD treated with 6MP developed shingles. In two with herpes zoster ophthalmicus the pain was prolonged, and one patient developed encephalitis which was brief and uncomplicated; in nine patients the course was benign. Acyclovir should be the treatment of choice even though it was available in only three cases.

Shingles occurs more often in IBD patients treated with 6MP than in those who are not, but the course is usually benign and there has been no mortality. The 6MP should be stopped temporarily until severity is established but if the underlying disease warrants further treatment the 6MP should be restarted.