T. Macleod, W. Frain-Bell
Mar 1, 1971
Citations
0
Influential Citations
49
Citations
Quality indicators
Journal
British Journal of Dermatology
Abstract
—Mexenone. Red Veterinary Petrolatum, benzyl salicylate and benzyl cinnaniate, para-aminobenzoic acid, and (Hhydrogyacetone (DHA)/ Lawsone, were studied by in vitro and in vivo methods in a group of normal subjects and in patients suffering from polymorphic light eruption, solar urticaria, porphyria, or xeroderma pigmentosum. It was found that a preparation with an apparent adequate protection factor in normal subjects not infrequently failed to give comparable protection in patients with abnormal skin responses either on phototesting or in clinical use. A combined chemical and physical light protective preparation (Cream ERl) was therefore formulated and shown to be more effective. The difficulty in prescribing light screening preparations without specific knowledge of the responsible wavebands is discussed, and attention is drawn to the frequent unreliability of in vitro studies as a means of determining the in vivo efficacy of a preparation.