Chronic urticaria is not significantly associated with hepatitis C or hepatitis G infection: a case-control study

OBJECTIVE: To study the prevalence of hepatitis C virus (HCV) and hepatitis G virus (HGV) infection in patients with chronic urticaria. DESIGN: Prospective case-control study and literature review. SETTING: Dermatology department of an academic medical center in Strasbourg, France. PATIENTS: One hundred ten consecutive patients with typical urticaria lasting longer than 2 months were seen between March 1, 1997, and August 31, 1998. None had a history of viral hepatitis. Age- and sex-matched patients (n = 110) seen in the same department and during the same period were included for controls. None of the controls had a history of urticaria, pruritic dermatosis, or hepatitis. MAIN OUTCOME MEASURES: The detection of HCV antibodies through a third-generation enzyme-linked immunosorbent assay. To detect early HCV infection without plasmatic antibodies, genomic amplification of HCV RNA was carried out in all patients using 2 different methods. Hepatitis G virus RNA was detected only by genomic amplification. All measures were planned before data collection. RESULTS: Antibodies to HCV were found in 1 patient with urticaria and in 1 of the control group (0.9% of each group). None had circulating HCV RNA, and liver function test results were within the reference range. Genomic amplification without HCV antibodies was not observed. Two patients with urticaria and 2 of the control group (1.8% of each group) had circulating HGV RNA, but they had neither coinfection with HCV nor changes in their liver function test results. CONCLUSIONS: Systematic HCV screening in patients with chronic urticaria is not cost-effective, at least in Europe, because hepatitis C rates were similar to those of the general population. We could not confirm the hypothesis that urticaria occurs in an early phase of HCV infection-ie, before evidence of HCV can be detected by serologic testing. Hepatitis C virus is unlikely to be the cause of urticaria in the infected patient detected in this study because of the absence of HCV RNA and changes on liver function tests. Hepatitis G virus is also unlikely to be a cause of urticaria, as the rate of HGV positivity in this study was even lower than that in the general French population.