The age of the patient with IBD or duration of treatment with immunosuppressive drugs do not help predict the risk of developing shingles.

The finding from a retrospective study of 30 Australian patients with IBD and herpes zoster means reactivation of the varicella zoster virus (VZV) can occur at any time.

Professor Jane Andrews, head of IBD services at the Royal Adelaide Hospital, told the limbic it was an important finding from a clinical point of view.

“It says that at any time during immunosuppression therapy we need to be suspicious of symptoms such as tingling or an odd rash.”

“Early treatment with antivirals is important for avoiding disabling complications such as post-herpetic neuralgia. If given late, the biggest problem from herpes zoster is ongoing pain. ”

She said the warning would also be relevant for the increasing numbers of patients with other chronic diseases requiring immunosuppression.

However it was possible the problem could wane in future generations who received the varicella vaccine as a child.

The study found patients with Crohn’s disease were more often affected by shingles than patients with ulcerative colitis. And the vast majority of patients (80%) with shingles had more severe IBD with penetrating, stricturing or perianal disease.

Of those taking immunosuppressive treatment, about one third were on monotherapy and two thirds were on dual therapy. Thiopurines were the most common treatment.

“Ideally, we need to have an effective prevention strategy through vaccination,” Professor Andrews said.

However a promising recombinant subunit vaccine is still not yet licensed in Australia, she noted.

“When patients are sick and need immunosuppressive treatment, we don’t have time to wait and immunise them against something they may not get.”

However patients in remission from Crohn’s disease can interrupt their immunosuppressive therapy for a few months without much trouble in order to recover from herpes zoster, she said.

The study found complications including post-herpetic neuralgia, herpes zoster ophthalmicus and secondary bacterial infections in 27% of the patients.

Two patients with persistent problems three years after their herpes zoster episode, did not have their immunosuppressive treatment withheld during the period of infection.