Erythrodermic psoriasis (EP) and erythroderma exfoliativa (EE) are acute and potentially life-threatening inflammatory reactions. We estimated hazard ratios (HRs) of 3-year mortality following hospitalization for EP or EE compared with general population controls, patients hospitalized for psoriasis vulgaris, and toxic epidermal necrolysis (TEN), respectively. We identified 26 and 48 patients with a first-time hospitalization (1997-2010) for EP and EE, respectively (10 matched population-controls for each patient), 1,998 patients with psoriasis vulgaris, and 60 patients with TEN. During follow-up, 8 (30.8%) patients with EP, 19 (39.6%) patients with EE, and 34 (56.7%) patients with TEN died. Compared with population-controls, adjusted HRs were 4.40 (95% CI 1.66-11.70) for EP and 2.16 (1.21-3.82) for EE. Compared with psoriasis vulgaris, adjusted HRs were 1.83 (0.90-3.73) for EP, and 1.28 (1.01-1.63) for EE. The risk was significantly lower in EP (0.38 (0.16-0.91)) and in EE (0.50 (0.36-0.71)), compared with TEN. Mortality in EP and EE is high, and close follow-up is advised.