Topical ALA and Red Wavelengths

Topical ALA application has also been shown to result in PpIX fluorescence at a higher level within acne lesions than in surrounding normal skin [15]. Subsequent exposure to red light was shown to shrink sebaceous glands [15]. Topical ALA for 3-hour incubation under occlusion followed by red broad-band light (550-700 nm) yielded significant improvement in acne counts, though side effects of blistering, erythema, edema, and dyspigmentation were reported [15]. In another study, topical ALA at 3-hour incubation followed by red diode laser (635 nm) demonstrated similar efficacy and side effects in the treatment of back acne [16]. In the aforementioned study, comparing blue (415 nm) to red (660 nm) light without ALA demonstrated that the longer red wavelengths enhanced efficacy rates, likely due to deeper penetration depth [10]. Similarly, in two studies of topical ALA at 4-hour incubation followed by red (635 nm) laser and polychromatic (600-700 nm) light, signifi­cant clearing of acne was observed, however, both light sources were accompanied by significant side effects of crusting and hyperpigmentation [17 , 18]. While effective, the combination of topical ALA with red wavelengths was associated with side effects of pain, erythema, blistering, crusting and dyspigmentation [19].