The Zumbusch pattern of generalized pustular psoriasis (GPP) classically presents as waves of widespread sheets of sterile pustules on brightly erythematous skin. The occurrence of this disease in childhood is rare, and fewer than 200 cases have been reported in the literature. We describe a 10-year-old boy with GPP who had an elevated serum antistreptolysin titer. Several antigenic factors shown to elicit GPP have been reported, including withdrawal of steroids, emotional stress, and infection. However, we further propose that the group A beta-hemolytic streptococcus can trigger a flare of GPP. We suggest that if pustular psoriasis is suspected clinically, an elevated serum antistreptolysin antibody titer may help identify the causative antigen.