Background:Pustular psoriasis of the digits (acrodermatitis continua of Hallopeau) may be localized to one or more digits for over an extended period of time. Characteristic presentation is that of tender, diffusely eroded, and fissured pustular plaques on one or more digits. Transition to other forms of psoriasis and to generalized pustular psoriasis is known to occur. These patients have an increased risk of acute generalized exanthematous pustulosis (AGEP) compared to the general population. Pustular psoriasis is often therapy resistant.Main observations:We report the case of a 54-year-old Caucasian woman who presented with a pustular psoriasis flare complicated by AGEP. Treatment course included hospital admission, cyclosporine, acitretin, and discontinuation of cephalexin.Conclusion:The precipitating factor in the course of treatment is thought to be cephalexin. When treating patients with pustular psoriasis the occurrence of druginduced complications should be carefully examined. Our case suggests that avoidance of β-lactam antibiotics in these patients is warranted unless absolutely indicated.