Impact of comorbidities on risk of angioedema without urticaria in elderly patients

BACKGROUND: Angioedema without urticaria (AWU) is a disease found in the elderly population but is still poorly studied. The aim of this study was to investigate potential factors, especially comorbidities, that may affect the induction of angioedema without urticaria in patients over 60 years of age. METHODS: This was an observational, retrospective study of 242 patients with a diagnosis of AWU and 263 controls. The inclusion criteria were as follows: at least one episode of confirmed AWU based on the ICD-10 code (T78.3) that required treatment in the last 15 years (2004–2019); age above 60 years; detailed medical history of comorbidities; and details regarding the use of drugs at that time. Serum functional and quantitative C1 inhibitor assays were performed, and serum C4 was measured. Comorbidities were grouped into the following panels: autoimmune, cancer, cardiac, metabolic, respiratory and allergic, liver failure and renal failure. Individual diseases were checked according to ICD code and treatment. RESULTS: In 1 (0.4%) patient, hereditary angioedema was confirmed. Decreased levels of C1INH were observed in 4 (1.65%) patients, dysfunction of C1INH was observed in 5 (1.76%) patients, and low levels of C4 were observed in 9 (3.71%) patients in the study group. The multiple logistic regression model revealed that patients with hyperuricemia or Hashimoto’s disease had a significantly higher chance of angioedema (OR = 3.21, 95% CI 2.92–3.66, p = 0.002; OR = 1.78 95% CI 1.37–2.21, p = 0.034, respectively). CONCLUSION: The obtained results may indicate a significant influence of hyperuricemia or Hashimoto’s disease on angioedema manifestations.