Elevated serum total IgE--a potential marker for severe chronic urticaria.

Background: Elevated IgE levels in patients with chronic urticaria have been noted previously, but the significance of these findings has not been appreciated.

Objective: To measure the IgE levels in such patients and to examine the relationship between these levels and urticarial severity, autologous serum skin test, anti-thyroid antibodies and duration.

Methods: Serum total IgE levels from 203 patients with chronic urticaria were measured and compared with nonatopic individuals. Additionally, patients were assessed for urticarial severity, the presence of autologous serum skin test and anti-thyroid antibodies.

Results: Of the chronic urticaria patients, 47 (23.2%) were classified as mild, whereas 67 (33%) were classified as having moderate and 89 (43.8%) as having severe chronic urticaria. Total IgE levels were elevated, above 175 U/ml, in 69/203 (34%) of patients, compared with 7/81 (8.6%) of healthy controls (p < 0.001). A significant association between increased total IgE and chronic urticaria severity was found. Whereas 93% of patients with increased level of total IgE suffered from moderate-to-severe chronic urticaria, this was observed in only 69% of patients with normal IgE (p < 0.0001). Autologous serum skin test and anti-thyroid antibodies were positive in 59/163 (36%) and 28/189 (15%) patients, respectively. A significant association between increased total IgE levels and the presence of autologous serum skin test, anti-thyroid antibodies and urticarial duration lasting more than 25 months (p < 0.0001, p < 0.0001 and p = 0.021, respectively) was also detected.

Conclusions: Total serum IgE levels are frequently elevated in patients with chronic urticaria and these are associated with disease severity and duration.