The dermatologist is called on to protect the skin of patients with dermatoses that result from, or are aggravated by, the sun's rays. In addition, persons with normal skins may wish to minimize the unpleasant effects of excessive sunlight to which they may be exposed at work or play. Protective measures to these ends consist almost entirely of the topical interposition of an external barrier between the skin and the source of radiation. Only very recently has it been suggested that certain drugs taken orally might protect the skin from the untoward effects of sunlight.
Topical applications may protect the underlying skin by scattering light rays so they never reach the light-reactive part of the skin. Opaque powders such as talc, zinc oxide (calamine), titanium oxide, as is or in shake lotions and ointments, protect in this way. Relatively heavy coatings of such mixtures are needed to