Hepatitis C virus infection in patients with urticaria.

BACKGROUND: Hepatitis C virus (HCV) infection induces variable skin manifestations.

OBJECTIVE: Our purpose was to determine whether there is an association between HCV infection and urticaria.

METHODS: Antibody to HCV (anti-HCV) and HCV genotypes were determined in patients with urticaria and in a control population.

RESULTS: Anti-HCV was detected in 19 (24%) of 79 patients with urticaria, and HCV RNA was detected in 17 (22%). Genotypes of HCV were II/1b in 12 (71%), III/2a in 4 (24%), and IV/2b in 1 (6%). The 17 patients with HCV RNA were older (53 +/- 14 vs 41 +/- 14 years, p < 0.01), and their eruption lasted longer (35% vs 6%, p < 0.05) and left pigmentation more frequently (53% vs 3%, p < 0.001). They had higher levels of alanine aminotransferase (67 +/- 34 vs 25 +/- 17 U/L, p < 0.001), aspartate aminotransferase (51 +/- 23 vs 21 +/- 8 U/L, p < 0.001), zinc turbidity test (12.8 +/- 3.1 vs 9.3 +/- 3.7 Kunkel units, p < 0.001), and IgG (1919 +/- 320 vs 1622 +/- 349 mg/100 ml, p < 0.01) than the patients without HCV RNA.

CONCLUSION: HCV could be a significant cause of urticaria. Chronic urticaria associated with HCV infection has peculiar clinical, serologic, and biochemical characteristics that could make it a distinct clinical entity with an indication for interferon therapy.