The research was carried out by a team at the Centre for Dermatology, part of the University of Manchester, who specifically set out to investigate the frequency of photoallergic and contact allergy in children under 18 years old.
Although there is significant data to show that chemicals in sunscreens can cause allergic reactions in adults, this is thought to be the first time that a study of this nature has targeted children, a group that invariably has high levels of photallergy compared to adults.
The team of scientists used photopatch testing to a standard series of nine ultraviolet filters and to sunscreen products in a single photoinvestigation centre.
Duplicate series of UV filters and the children's own sunscreen products were applied to the back, with readings taken at sample removal, and at 24 and 48 h after the UV exposure.
The analysis comprised 157 children aged 3–17 years, and the results showed that a total of ten children showed positive photopatch responses to UV filters and/or their sunscreen products (4·5% to UV filters, 5·7% to their sunscreen products).
Benzophenone-3 and octyl methoxycinnamate
The responsible UV filters most often identified were benzophenone-3 and octyl methoxycinnamate, and the researchers noted that additionally, contact allergy reactions were observed in nine children with 16 children showing photoallergy and/or contact allergy to UV filters and/or sunscreen products.
The researchers claim that this is the largest photopatch testing of children for sunscreens and suggests that they have a particularly high incidence of photoallergy and/or contact allergy to UV filters and sunscreens.
Ultimately, the researchers say they believe that widespread photopatch testing should be introduced to children who show symptoms of photosensitivity.