Psoriasis is characterized by a T-helper (Th)1/Th17 immune response, and an increase in IgE levels is a prototypical marker of Th2 immunity. The aim of this retrospective case–control study was to analyse serum total IgE levels in generalized pustular psoriasis (GPP), a rare and severe variant of psoriasis. The levels of IgE in patients with GPP and patients with psoriasis vulgaris (PV) were compared with those of healthy controls. IgE levels were also compared with the levels of C-reactive protein (CRP), an indicator of systemic inflammation. The percentage of patients with GPP who had increased IgE levels was significantly higher than that of patients with PV and of healthy controls. The mean levels of IgE were also higher in the GPP group. The IgE levels in patients with GPP had a significant positive correlation with CRP levels. We hypothesize that serum IgE level is a general indicator for increased inflammation in GPP and PV.