Individual consideration of the patient is an accepted fundamental of good clinical management of scarlet fever. A distinctly different principle guides current practice in control measures designed to protect the public against this infectious disease. Isolation is largely a group procedure, with requirements governing the disease rather than the individual concerned. Incomplete information on the epidemiology of scarlet fever is one outstanding reason for this empiric practice, based as it is on an arbitrary time element and accumulated practical experience. Lacking facts, general measures must be prescribed. However, inertia of accepted practice and the convenience of public health authority probably also contribute. Better cooperation in reporting and maintaining isolation can logically be expected, if restrictions are minimal and adjusted to individual requirements. Group control is not entirely satisfactory. Inadequate protection is afforded a community because of failure to recognize individual differences in communicability among patients convalescing from scarlet fever. Moreover,