Asthma is an unrecognized risk factor for herpes zoster (shingles) in adults, and clinicians should consider vaccinating asthmatics at least 50 years old as a target group, according to a study published online December 28 in the Journal of Allergy and Clinical Immunology.

Researchers identified 371 cases with shingles during the study and compared them against 742 control patients. Of the 371 shingles cases, 23% (87 people) had asthma compared with 15% (114/742) from the control group.

The authors found that adults with asthma were at about a 70% greater risk of developing shingles compared with those without asthma. The population-attributable risk percentage for asthma was about 10%.