We report a 2-year-old girl with diffuse pustular eruptions occurring in close association with respiratory tract infections. The pustular eruption had different clinical characteristics over time, evolving from circinate to von Zumbush pustular psoriasis, and finally to subcorneal pustular dermatosis. Treatment with acitretin 1 mg/kg/day gave good results. A relapse showing striking clinical characteristics of subcorneal pustular dermatosis was treated with dapsone (1 mg/kg/day) followed by ultraviolet B-narrowband (UV-B-NB) phototherapy. The patient subsequently had several relapses over 1 year, which were well controlled with short cycles of UV-B-NB. This patient's findings demonstrate that pustular eruptions can vary over time, assuming clearly different clinical patterns, and highlight the difficulty of classifying pustular eruptions as separate diseases.