Researchers at the London School of Hygiene and Tropical Medicine reported in a study published in BMJ that patients with autoimmune diseases and other chronic illnesses face an increased risk for herpes zoster, or what is commonly referred to as shingles. Risk factors cited by the authors include lupus, rheumatoid arthritis (RA), chronic obstructive pulmonary disease (COPD), inflammatory bowel disease, asthma, chronic kidney disease, diabetes, and depression.
The study, led by Harriet J. Forbes, looked at 144,959 cases of shingles in the United Kingdom between 2000 and 2011. Sixty percent were women. Median age at diagnosis was 62. A total of 65% of the cases were in patients younger than 70; 45% were younger than 60.
Forbes and her team used statistical analysis to estimate how closely associated the potential risk factors were with shingles outcomes. Specifically, the team calculated odds ratios (OR) for each autoimmune condition. The OR is simply the odds that an outcome will occur given a particular exposure or condition. For example, an OR of 1 would mean that the autoimmune condition had no effect on the odds of the outcome, in this case, development of shingles.
Results of the study indicated that the OR for patients with lupus was 1.72. RA patients proved to have an OR of 1.46, while those with COPD had an OR of 1.32. The team also found increased risk for shingles in patients with inflammatory bowel disease (OR = 1.36), asthma (OR = 1.11), chronic kidney disease (1.12), depression (1.15), and Type I diabetes (1.26).
In addition, the relative effect of the risk factors analyzed was larger in younger patients. What’s more, patients with severely immunosuppressive conditions were at greatest risk of shingles. These included patients with lymphoma, myeloma, and HIV. However, the shingles vaccine is contraindicated for these patients.
The researchers concluded that several autoimmune diseases and other chronic conditions significantly raised the risk of shingles. Given this finding, it was proposed that alternative risk reduction strategies be developed for groups of patients for whom the shingles vaccine is not indicated.
Reference: Forbes, H. et al. Quantification of risk factors for herpes zoster: population based case-control study. BMJ 2014; DOI: 10.1136/bmj.g2911.