Photoallergy to Benzophenone

Abstract

Incorrect diagnosis of photoallergy to sunscreen products represents a unique clinical dilemma. Increasing sunscreen usage for suspected idiopathic photosensitivity or a change to a sunscreen containing the same photoallergen only worsens the problem. While photoallergy to p-aminobenzoic acid and its esters is well known by dermatologists and the lay public, benzophenone photoallergy is not well appreciated. We report herein the cases of four individuals with photoallergy to oxybenzone in sunscreens. It is likely that such reactions will become more commonplace since oxybenzone is by far the most frequently used agent in modern, high sun protection factor sunscreens (greater than 8 sun protection factor) being marketed today.

Benzophenone 4: an emerging allergen in cosmetics and toiletries?

“…The benzophenones are a group of chemical UVA filters whose broad spectrum of protection extends into the UVB range. 4 benzophenones namely benzophenone 3, benzophenone 4, benzophenone 8 (2,2‐dihydroxy‐4‐methoxybenzophenone: dioxybenzone) and benzophenone 10 (2‐hydroxy‐4‐methoxy‐4‐methylbenzophenone: mexenone) have historically been incorporated into sunscreens and cosmetics with benzophenone 3 being by far the most commonly used (4). Such a frequency of use has, no doubt, contributed to the finding that benzophenone 3 has been the most commonly reported UV filter producing positive patch test results (3, 5–8).…”

Photoallergic Contact Dermatitis

“…This new dibenzoylmethane has been reported to cause photocontact allergy in Europe and will probably be found to do the same in this coun¬ try once usage reaches a high level. 7 Photopatch testing should be an integral part of the workup of most photosensitive patients. It is the only way to diagnose PACD that is responsible for 10% to 20% of disease in the photosensitive population re-ferred to tertiary centers.…”

Experimental study on phototoxicity and the photosensitization potential of ketoprofen, suprofen, tiaprofenic acid and benzophenone and the photocross‐reactivity in guinea pigs

“…Oxybenzone is an ingredient of topical ketoprofen products used to protect the products from being degraded by sunlight. It is the most frequently used UV‐absorbent in modern, high sun protection factor sunscreens marketed today (28). We reported on four cases with ketoprofen photoallergy (2) who reacted negatively to oxybenzone with photopatch testing (Table 5).…”