Actinic reticuloid: action spectra and UVA protection factor sunscreens

This study compares the action spectra on two new patients with actinic reticuloid (AR), with one previously reported patient. All three patients had exquisite photosensitivity in the UVB range being up to 27 times more sensitive than controls. Sensitivity also increased into the UVA Range, all up to 335 nm and, one into the visible. Their photosensitivity made evaluation of the Sun Protection Factor (SPF) of selected, more recent, high-numbered sunscreens easier to compare, because of the shorter time of the minimal erythema dose when tested with a solar simulator. A sunscreen containing butyl methoxydibenzoylmethane (Parsol 1789) with an overall SPF of 16 was not as effective at protecting the actinic reticuloid patients as a higher SPF numbered sunscreen containing a benzophenone (SPF of 40). The Parsol 1789 gave a protection value of 5 in the UVA Range, compared to one of 3 given by the sunscreen containing benzophenone. The SPFs of seven of these commerically available high-numbered sunscreens were compared with controls.