Photo-allergic contact dermatitis caused by isoamyl p-methoxycinnamate in an 'organic' sunscreen.

A 39-year-old female presented with a 20-year history of a polymorphic, urticated and papular eruption occurring on sun-exposed sites but sparing the face and hands. She had been referred because, after many years of sunscreen use, she had begun to develop an exacerbation of her rash at sites of application of a new sunscreen, including, for the first time, the face. She described an urticated eruption at the site of application of this sunscreen that would settle after several days with scaling. This was an ‘organic’ sunscreen purchased online, and claimed to be natural and ‘‘made without parabens, lanolin, phthalates, artificial perfumes, petrochemicals and colorants to bring you the purest sunscreen that nature can offer’’.