Twenty-eight patients with dermatologic reactions to infection with phage group II staphylococci are described. Reactions in the skin included: generalized exfoliative disease in infants (Ritter's disease) and in children (toxic epidermal necrolysis), generalized scarlatiniform erythema without exfoliation (staphylococcal scarlet fever), and localized bullous impetigo. The generalized exfoliative disease in the newborn infant or in older chlidren and bullous impetigo have previously been associated with this particular organism, but nonstreptococcal scarlatiniform eruption has not. These various clinical manifestations of infection with the phage group II staphylococcus present a spectrum of disease with a single etiology. Utilizing an experimental model, methicillin therapy was demonstrated to be effective in ameliorating the course of the disease; treatment with corticosteroids had no beneficial effect.