Dermatology Department, State University of Rio de Janeiro (UERJ), Rio de Janeiro, Brazil.
Dermatology Departament, Central Aeronautics Hospital (HCA), Rio de Janeiro, Brazil.
Skin Res Technol. 2020 Nov;26(6):876-882. doi: 10.1111/srt.12889. Epub 2020 Jun 26.
Actinic keratosis (AK) incidence is increasing. Due to the risk of progression to squamous cell carcinoma, early detection and treatment are essential. The method stated in the European Consensus is cryotherapy, but there is no standard protocol defined for better results.
To compare two different cryotherapy protocols for AK using reflectance confocal microscopy (RCM) as a noninvasive imaging method for evaluation.
A self-controlled clinical trial was proposed to compare the efficacy of cryotherapy in two different application protocols. Grade II AKs in the forearms were submitted to freezing and thawing time of 10 seconds for 1 cycle (group A) or 2 cycles (group B). At baseline and 4 weeks after treatment, the same dermatologists assessed RCM evaluation (thickness of horny layer, parakeratosis, dyskeratosis, atypia in spinous layer, fibrosis, and presence of inflammatory cells in epidermis and dermis).
We examined 24 AK lesions in each group. Statistical evaluation of the results evidenced superior response after 2 cycles of cryotherapy in parakeratosis and number of inflammatory cells in epidermis.
Both protocols are effective in clearing clinical AK. Two cycles are not generating more side effects (fibrosis) and could reduce the risk of recurrence (better "clearance" of parakeratosis).
光化性角化病（AK）的发病率正在增加。由于有进展为鳞状细胞癌的风险，因此早期发现和治疗至关重要。欧洲共识中提到的方法是冷冻疗法，但为了获得更好的效果，还没有定义标准的方案。
使用反射共聚焦显微镜（RCM）作为非侵入性成像方法，比较两种不同的 AK 冷冻疗法方案。
提出了一项自身对照临床试验，以比较两种不同应用方案的冷冻疗法的疗效。在前臂的 II 级 AK 接受 10 秒的冷冻和解冻时间（A 组）或 2 个周期（B 组）。在基线和治疗后 4 周，同一位皮肤科医生评估 RCM 评估（角质层厚度、角化不全、非典型棘层角化、纤维化以及表皮和真皮中炎症细胞的存在）。
我们在每组中检查了 24 个 AK 病变。结果的统计评估表明，在冷冻治疗 2 个周期后，角化不全和表皮中炎症细胞的数量有更好的反应。
两种方案都能有效清除临床 AK。两个周期不会产生更多的副作用（纤维化），并可能降低复发的风险（更好地清除角化不全）。
