Santos Maria Arianee V, Belo Victoria G, Santos Guada
Dermatol Surg. 2005 Aug;31(8 Pt 1):910-5. doi: 10.1097/00042728-200508000-00004.
Photodynamic therapy (PDT) involves the activation of a photosensitizing agent by light to produce oxygen intermediates that destroy target tissues. Topical 5-aminolevulinic acid (ALA) is converted to protoporphyrin IX, a very potent photosensitizer, which accumulates in human skin, particularly in the epidermis and its appendages.
To study the effect of PDT in acne vulgaris using topical ALA and intense pulsed light (IPL).
Thirteen individuals with varying degrees of acne were treated after a 3-week washout period. Twenty percent ALA hydrochloride (DUSA Pharmaceuticals, Wilmington, MA, USA) was applied to half of the face, and after 3 hours, the whole face was exposed to intense pulsed light (Quantum SR, Lumenis, Santa Clara, CA, USA) using a 560 nm cutoff filter starting at a fluence of 26 J/cm. The procedure was done twice at 2-week intervals, and the patients were clinically evaluated on the second, fourth, and eighth weeks.
All patients had no apparent improvement on the second week on both facial halves. In fact, some of the patients developed acute acneiform eruptions on the side treated with ALA. By the fourth week, however, most of the patients had visible improvement of facial acne that was more significant on the ALA-treated side of the face. This persisted until the eighth week post-treatment. On the other hand, the facial half treated with intense pulsed light only showed a return to baseline of their facial acne.
ALA-IPL are beneficial in the management of acne vulgaris and may be used in combination with other forms of acne treatment or may be an alternative treatment for patients who do not want to take systemic retinoids.
光动力疗法(PDT)是通过光激活光敏剂以产生破坏靶组织的氧中间体。外用5-氨基酮戊酸(ALA)可转化为原卟啉IX,这是一种非常有效的光敏剂,其在人体皮肤中蓄积,尤其是在表皮及其附属器中。
研究使用外用ALA和强脉冲光(IPL)的光动力疗法治疗寻常痤疮的效果。
13名不同程度痤疮患者在经过3周的洗脱期后接受治疗。将20%的盐酸ALA(美国马萨诸塞州威尔明顿市DUSA制药公司)涂于半侧面部,3小时后,使用560nm截止滤光片,从26J/cm²的能量密度开始,对整个面部进行强脉冲光照射(美国加利福尼亚州圣克拉拉市Lumenis公司的Quantum SR)。该操作每2周进行一次,共进行两次,在第2、4和8周对患者进行临床评估。
在第2周时,所有患者两侧面部均无明显改善。事实上,一些患者在接受ALA治疗的一侧出现了急性痤疮样皮疹。然而,到第4周时,大多数患者面部痤疮有明显改善,在接受ALA治疗的面部一侧更为显著。这种改善一直持续到治疗后第8周。另一方面,仅接受强脉冲光治疗的半侧面部痤疮仅恢复到基线水平。
ALA-IPL对寻常痤疮的治疗有益,可与其他形式的痤疮治疗联合使用,或可作为不想服用系统性维甲酸的患者的替代治疗方法。