Urticaria is a mast cell-related disorder that can cause severe itching. The lifetime incidence of urticaria in general population is approximately 20%. The main objective of this cohort study is to evaluate the risk of urticaria in geriatric stroke patients who had received influenza vaccination (IV).

Almost 192,728 patients with newly diagnosed stroke, aged more than 65 years were obtained from 23 million people in Taiwans National Health Insurance between 2000 and 2008 and were included in the cohort. Among them, 9890 stroke patients who received IV and 9890 propensity score-matched stroke patients who did not receive IV were identified. Monitoring the immortal time preference, both the IV and non-IV groups were followed for almost one year. Urticaria events were observed during the follow-up period.

During the follow-up one year period, stroke patients with IV had a significantly higher risk of urticaria as compared to non-IV stroke patients. A higher risk of urticaria in stroke patients with IV was also observed in both sexes, patients with comorbid medical conditions, patients 65-84 years of age and various time intervals of follow-up. Stroke patients who were vaccinated with hemorrhage and those who received intensive care had a considerable high risk of urticaria as compared to those without IV.

The study concluded that receiving IV could be associated with an increased risk of urticaria in stroke patients.

Source: Lam F, Shih CC, Chen TL, et al. Risk Of Urticaria In Geriatric Stroke Patients Who Received Influenza Vaccination: A Retrospective Cohort Study. Clin Interv Aging. 2019; 14:2085‐2093. Published 2019 Nov 26. doi:10.2147/CIA.S228324