Deonizio Janyana, Werner Betina, Mulinari-Brenner Fabiane A
Dermatology Department, Federal University of Parana, Rua General Carneiro, 181 Alto da Glória, 80060-900 Curitiba, PR, Brazil.
Pathology Department, Federal University of Parana, Rua General Carneiro, 181 Alto da Glória, 80060-900 Curitiba, PR, Brazil.
ISRN Dermatol. 2014 Mar 12;2014:950754. doi: 10.1155/2014/950754. eCollection 2014.
Background. Cryopeeling is a technique that uses cryotherapy not only on actinic keratoses lesions, but also all over the photodamaged skin. Objectives. To investigate the histological changes induced by two cryopeeling methods (liquid nitrogen (LN) and portable system (PS)). Methods. Sixteen patients (n = 16) with multiple actinic keratoses on the forearms were treated with cryopeeling technique using LN for one forearm and PS for the other, randomly. Skin biopsies were taken before and after the procedures. Results. There was no statistical difference between the epidermal and Grenz zone thicknesses or density of elastic fibers after treatments. The amount of melanin pigment was lower after PS treatment (P < 0.05). In a blind analysis of paired pre- and postprocedure slides, it was not possible to identify cases which underwent treatment, both in global analysis of quality of the skin and in specific analysis (considering only the aspect of stratum corneum). Discussion. The results indicate the inconsistency of histological improvement after treatments, and, likely, since the method causes superficial exfoliation, a reliable marker was not found in the analysis. Conclusions. Despite cosmetic benefits on photodamaged skin and efficient treatment of actinic keratoses lesions, cryopeeling was not able to induce measurable histological changes in solar elastosis, epidermal organization, or epidermal and Grenz zone thicknesses. One should keep in mind the possibility of hypopigmentation risk of the method.
背景。冷冻脱皮术是一种不仅用于光化性角化病皮损，还用于整个光损伤皮肤的冷冻疗法技术。
目的。研究两种冷冻脱皮方法（液氮（LN）和便携式系统（PS））所引起的组织学变化。
方法。对16例前臂有多处光化性角化病的患者，随机采用液氮冷冻脱皮术治疗一侧前臂，便携式系统治疗另一侧前臂。在治疗前后取皮肤活检样本。
结果。治疗后表皮和无细胞层厚度或弹性纤维密度之间无统计学差异。便携式系统治疗后黑色素含量较低（P < 0.05）。在对治疗前后配对玻片进行盲法分析时，无论是在皮肤质量的整体分析还是在特定分析（仅考虑角质层方面）中，都无法识别接受过治疗的病例。
讨论。结果表明治疗后组织学改善不一致，而且可能由于该方法导致表皮剥脱，在分析中未找到可靠的标志物。
结论。尽管冷冻脱皮术对光损伤皮肤有美容效果且能有效治疗光化性角化病皮损，但它无法在日光性弹力纤维变性、表皮组织结构或表皮和无细胞层厚度方面引起可测量的组织学变化。应牢记该方法存在色素减退风险的可能性。
