Superantigens differ from conventional antigens in a number of important ways, including polyclonal B-cell activation, extensive proinflammatory cytokine production, and changes in the number of circulating T lymphocytes that bear a specific surface receptor (specifically Vβ-restricted T cells). Superantigens are able to bypass antigen-presenting cells, binding directly to the major histocompatibility complex class II (MHC II) complex outside of the groove of lymphocytes. Therefore, they are able to stimulate nonspecific T-cell proliferation and may activate as many as 20% to 30% of circulating lymphocytes. This T-cell expansion leads to massive cytokine production, especially tumor necrosis factor α, interleukin 1, and interleukin 6. These cytokines lead, in turn, to various different clinical signs, such as fever, hypotension, emesis, diarrhea, shock, and cutaneous eruptions. The spectrum of diseases mediated by superantigens caused by toxins made by staphylococci and streptococci encompasses some well-known older diseases (eg, scarlet fever and staphylococcal scalded skin syndrome) and some lesser-known diseases such as toxic shock syndrome, streptococcal toxic shocklike syndrome, recalcitrant erythematous desquamating disorder, and recurrent toxin-mediated perineal erythema (RTPE),1- 3 which was first described by Manders et al6 in 2 healthy young adult men. We describe herein 11 cases of RTPE in children.