Topical ALA-Photodynamic Therapy for the Treatment of Acne Vulgaris

Abstract

Topical aminolevulinic acid is converted into a potent photosensitizer, protoporphyrin, in human hair follicles and sebaceous glands. Photodynamic therapy with topical aminolevulinic acid was tested for the treatment of acne vulgaris, in an open-label prospective human study. Each of 22 subjects with acne on the back was treated in four sites with aminolevulinic acid plus red light, aminolevulinic acid alone, light alone, and untreated control. Half of the subjects were treated once; half were treated four times. Twenty percent topical aminolevulinic acid was applied with 3 h occlusion, and 150 J per cm2 broad-band light (550-700 nm) was given. Sebum excretion rate and auto-fluorescence from follicular bacteria were measured before, and 2, 3, 10, and 20 wk after, treatment. Histologic changes and protoporphyrin synthesis in pilosebaceous units were observed from skin biopsies. Aminolevulinic acid plus red light caused a transient acne-like folliculitis. Sebum excretion was eliminated for several weeks, and decreased for 20 wk after photodynamic therapy; multiple treatments caused greater suppression of sebum. Bacterial porphyrin fluorescence was also suppressed by photodynamic therapy. On histology, sebaceous glands showed acute damage and were smaller 20 wk after photodynamic therapy. There was clinical and statistically significant clearance of inflammatory acne by aminolevulinic acid plus red light, for at least 20 wk after multiple treatments and 10 wk after a single treatment. Transient hyperpigmentation, superficial exfoliation, and crusting were observed, which cleared without scarring. Topical aminolevulinic acid plus red light is an effective treatment of acne vulgaris, associated with significant side-effects. Aminolevulinic acid plus red light causes phototoxicity to sebaceous follicles, prolonged suppression of sebaceous gland function, and apparent decrease in follicular bacteria after photodynamic therapy. Potentially, aminolevulinic acid plus red light may be useful for some patients with acne.

Blue and red light combination LED phototherapy for acne vulgaris in patients with skin phototype IV

“…ALA-PDT can be beneficial for acne particularly because it destroys pilosebaceous units as well as P. acnes [52][53][54]. Although its efficacy has been reported with variable mean percentage reduction rates from 32% to 72% according to different authors [55][56][57][58][59][60][61][62], ALA-PDT would not appear to offer significant advantage in the treatment of acne, particularly when the adverse effects of considerable long-lasting post inflammatory hyperpigmentation (PIH) following severe acute local reactions are taken into account, which is especially the case in dark-skinned individuals of Asian origin [19,55,[58][59][60][61][62]. In addition, the time lapse for ALA incubation and the necessity of vigorous sun protection to avoid potential phototoxic reactions for several days after ALA-PDT may decrease the patients' satisfaction level regarding this therapy [19].…”

“…Two of them complained of a transient, mild flare-up of previous acne lesions after the blue light treatments, which did not occur after red light treatment. A possible explanation for this phenomenon is that the debris of destroyed P. acnes may initiate an inflammatory response by recruiting neutrophils and stimulating the release of complements [55,63,64]. The temporary eruption disappeared spontaneously after 1-2 days.…”

Inativação fotodinâmica de microrganismos

“…PDI com aplicação tópica de ALA e aplicação de luz vermelha foi testada em 22 pacientes com acne vulgaris nas costas. Foi observada a eliminação da acne inflamatória que persistiu por pelo menos 20 semanas 21 .…”

Treatment of Acne in Pregnancy

“…Compared with control treatment, photodynamic therapy resulted in a statistically significant improvement in acne severity, along with sustained results for up to 20 weeks after multiple treatments. 34,35 The lack of insurance coverage and the frequency of required sessions at a dermatologist's office may present barriers to use.…”