Oh C W, Myung K B
Department of Dermatology, Gyeongsang National University, Chinju, Korea.
J Dermatol. 1996 Mar;23(3):169-80. doi: 10.1111/j.1346-8138.1996.tb03993.x.
The precise pathologic processes of comedo formation in acne are not well understood. Retention hyperkeratosis may play an important role. To evaluate the effects of three topical comedolytics, 20% azelaic acid, 0.1% tretinoin and 5% benzoyl peroxide, on the retention hyperkeratosis of experimentally induced comedones (EIC), an ultrastructural study was done. After formation of EIC with 50% oleic acid in paraffin oil on the external ears of rabbits, each comedolytic was applied for 4 weeks. Biopsies were taken every week and, using a Hitachi H-600 transmission electron microscope, morphologic observations were done in the upper portion of the follicular epithelium. In EIC, after application of each comedolytic, the markedly thinned horny layer was loosely adhered by extremely few desmosomes and desmosomal bodies. The number and size of tonofilaments and keratohyaline granules decreased, but the number of variable sized Odland bodies increased in the upper epidermis. These findings appeared 1 week after application of either azelaic acid or benzoyl peroxide, and 3 weeks after application of tretinoin. For the first 2 weeks of tretinoin application, EIC showed rather compact hyperkeratosis with more desmosomes and desmosomal bodies than before. Azelaic acid tretinoin and benzoyl peroxide increased the number of Odland bodies, and the horny cells became less adhesive. This lysis of retention hyperkeratosis resulted in comedolysis. During 4 weeks of treatment with these three comedolytics, only tretinoin normalized the keratinization process.
痤疮中粉刺形成的确切病理过程尚未完全明了。潴留性角化过度可能起重要作用。为评估三种外用粉刺溶解剂（20%壬二酸、0.1%维甲酸和5%过氧化苯甲酰）对实验性诱导粉刺（EIC）的潴留性角化过度的影响，进行了一项超微结构研究。在兔外耳用石蜡油中的50%油酸形成EIC后，每种粉刺溶解剂应用4周。每周进行活检，并使用日立H - 600透射电子显微镜对毛囊上皮上部进行形态学观察。在EIC中，应用每种粉刺溶解剂后，明显变薄的角质层通过极少的桥粒和桥粒小体松散附着。张力细丝和透明角质颗粒的数量和大小减少，但表皮上部大小不一的奥尔德小体数量增加。这些发现于应用壬二酸或过氧化苯甲酰1周后以及应用维甲酸3周后出现。在应用维甲酸的前2周，EIC显示出比以前更紧密的角化过度，桥粒和桥粒小体更多。壬二酸、维甲酸和过氧化苯甲酰增加了奥尔德小体的数量，角质细胞的黏附性降低。这种潴留性角化过度的溶解导致了粉刺溶解。在用这三种粉刺溶解剂治疗的4周期间，只有维甲酸使角化过程恢复正常。
