Photoallergic Contact Dermatitis due to Combined UVB (4-Methylbenzylidene Camphor/Octyl Methoxycinnamate) and UVA (Benzophenone-3/Butyl Methoxydibenzoylmethane) Absorber Sensitization

Abstract

In a 71-year-old male Caucasian patient with persistent eczema on light-exposed skin, photocontact allergy was demonstrated to the UV filter substances 4-methylbenzylidene camphor (UVB), octyl methoxycinnamate (UVB), benzophenone-3 (UVA) and butyl methoxydibenzoylmethane (UVA) present in sunscreen products used by the patient over several years. A significantly reduced UVB sensitivity of 25 mJ/cm² in this patient (normal minimal erythema dose in our laboratory = 70–130 mJ/cm²) was considered an early indication of a persistent light reaction. Topical anti-inflammatory treatment over 2 weeks together with consequent application of a sunscreen containing Mexoryl^® SX/titanium dioxide led to complete remission.Taking into account the widespread use of the above UV filter substances not only in sun protection products, but also in cosmetics such as antiaging lotions and day care products, the possible risk of allergy to these chemicals has to be taken seriously. The substitution of known photocontact sensitizers in UV filters by photostable compounds and detailed product information are the basis of preventive strategies.

Allergic Contact Dermatitis from Cosmetics

“…facial creams) of compounds absorbing UV radiation, we have not noticed a parallel increase in ACD in our department [18,19] (photo patch testing has been performed in every case of clinical suspicion).…”

Photoallergic contact dermatitis caused by ultraviolet filters in different sunscreens

“…Hence, this agent is most probably the key sensitizer responsible for the cutaneous reaction in the individual presented here. Members of the dibenzoylmethanes can cause both allergic and photoallergic contact dermatitis; however, 4‐ tert ‐butyl‐4‐methoxy‐dibenzoylmethane is a less common photosensitizer within this group of compounds, which absorb wavelengths throughout the longer UVA range and also contain 4‐isopropyl‐dibenzoylmethane 5–8,11,12 …”

Photoprotection

“…161 Contact and photocontact sensitivity to sunscreens has been reviewed; currently, Bp-3, a commonly used UVA filter, is the most common photoallergen. 162,163 UVA filters such as isopropyl dibenzoyl methane (Eusolex 8020; removed from the market in 1993), 164 avobenzone (butyl methoxydibenzoyl methane; Parsol 1789), [164][165][166][167][168] oxybenzone (Bp-3), 169 and sulisobenzone (Bp-4), and UVB filters such as PABA, padimate O (octyl dimethyl PABA), methylbenzylidene camphor, 166 octinoxate (OMC), and ensulizole ( phenylbenzimidazole sulfonic acid) 162,170 have all been reported to induce contact allergic and photoallergic reactions. It should be emphasized that considering the widespread use of sunscreen, contact and photocontact allergic reactions to sunscreen are uncommon.…”