光化性角化病是由于紫外线过度暴露引起的表皮损伤。它们也是皮肤癌变的初始阶段，通常出现在40岁以后。皮肤白皙、金色或红色头发、蓝色或绿色眼睛的人最容易患上这些表现为粗糙、伴鳞屑的斑块或角化的疾病。晒伤史也可能增加患此病的风险。如果不进行治疗，这些斑块有一小部分可能会发展成更严重的皮肤癌。

那么光化性角化病到底是怎样的？如何治疗？让我们一起来看看～
Actinic keratoses（AK） describes lesions on the outer skin layer caused by too much exposure to the ultraviolet rays of sunlight. They are also the beginnings of skin cancer, most often appearing after age 40.People with fair skin, blond or red hair, and blue or green eyes are most at risk of developing these rough, scaly patches, or keratoses. A history of a sunburn also increases the risk. If not treated, these patches can develop into a more serious form of skin cancer, although this is unusual.

So what οn earth are the symptoms of actinic keratosis? And how to prevent or treat them? Let's take a look at it together.

01

光化性角化病临床表现是怎样的？

What are the clinical symptoms for Actinic Keratoses？

光化性角化病病变通常是无症状的，但可能触痛、瘙痒、出血或产生刺痛或灼烧感。通常根据他们的临床表现分为3级：I级（肉眼可见，稍可触诊），II级（肉眼可见，可触诊）和III级（明显，过度角化）。光化性角化病通常发生在面部、嘴唇、耳朵、秃头、肩膀、颈部和手背和前臂。直径从一个小点到一英寸，大小不等。

The  lesions of actinic keratoses are usually asymptomatic, but can be  tender, itch, bleed, or produce a stinging or burning sensation. AKs are  typically graded in accordance with their clinical presentation: Grade I  (easily visible, slightly palpable), Grade II (easily visible,  palpable), and Grade III (frankly visible and hyperkeratotic). Actinic  keratoses typically occur on the face, lips, ears, bald scalp,  shoulders, neck and back of the hands and forearms. Ranging in size from  a tiny spot to as much as an inch in diameter .

02

光化性角化病如何诊断？Diagnosis

一般临床医生可通过肉眼判断您是否患有光化性角化病。如果有任何诊断困难，医生可能会进行其他检查，例如皮肤镜、皮肤活检。而皮肤活检是在皮损上取一小份样本进行实验室分析。通常于局部麻醉下在皮肤科门诊进行。即使在光化性角化病治愈后，您的医生可能会建议您每年至少检查一次是否有皮肤癌的迹象。皮肤癌若早期发现并接受治疗，治愈几率很大。
Diagnosis -Your doctor will likely be able to determine whether you have an actinic keratosis simply by examining your skin. If there's any doubt, your doctor may do other tests, such as a dermato-scopy or a skin biopsy. A dermato-scopy is using a magnifying lens to look at the suspected lesion. During a skin biopsy, your doctor takes a small sample of your skin for analysis in a lab. A biopsy can usually be done in the outpatient clinic after a numbing injection. Even after treatment for actinic keratosis, your doctor will likely suggest that you have your skin checked at least once a year for signs of skin cancer. When found early and treated, skin cancer is often cured.

03

光化性角化病如何预防？Prevention

为了预防光化性角化病，重要的是：
√ 在高峰日照时间（上午10点至下午2点）避免暴露在阳光下。
√ 穿上覆盖手臂和腿部的衣服。
√ 戴宽边帽，这样可以保护耳朵，也可以带伞。在户外阳光充足的高峰时段。
√ 使用防晒系数（SPF）为30或更高的防晒霜，在晒太阳前至少15至30分钟使用。选择标有“广谱”的防晒霜，及提供UVA和UVB防护。
√ 在室外，每两小时涂一次防晒霜，即使在阴天也是如此。
√ 请记住，太阳光中，对我们造成伤害的是光线而不是热量。所以即使环境温度不高，你也可能处于光线的危害之中。    
To prevent actinic keratosis, it's important to:                      
√ Avoid exposure to sunlight during peak sunlight hours (10 a.m. to 2 p.m.).                         
√ Wear clothing that covers arms and legs.                                 
√ Wear a wide-brimmed hat that protects the ears not just a cap or carry an umbrella, when outdoors during peak sunlight hours.
√ Use sunscreen with sun protection factor (SPF) of 30 or higher, applying it at least 15 to 30 minutes before sun exposure.             
√ Choose a sunscreen labeled “broad-spectrum” or states that it provides both UVA and UVB protection.
√ Reapply sunscreen every two hours when outdoors, even on cloudy days.                                                  

√ Remember that it is the light from the sun that can be dangerous not the heat  so you can be at risk even if the temperature  is mild.

04

光化性角化病如何治疗？Treatment

光化性角化病有时会自行消失，但通常在暴露于阳光后会复发。因为不可能分辨哪些斑块或病变会发展成皮肤癌，所以通常会通过治疗光化性角化病进行预防。有以下方法：
An actinic keratosis sometimes disappears on its own, but it typically returns after more sun exposure. Because it's impossible to tell which patches or lesions will develop into skin cancer, actinic keratoses are usually removed as a precaution. Available treatment are as follows: 

外用药物（免疫调节剂治疗）：咪喹莫特乳膏，巨大戟素凝胶或双氯芬酸凝胶的作用与氟尿嘧啶非常相似，可以选择性地清除皮肤异常细胞。副作用是可能红肿，瘙痒，肿胀和结痂。

Topical treatment（Immunomodulator therapy）: Imiquimod cream, ingenol gel, or diclofenac gel works much like fluorouracil to selectively rid the skin of abnormal cells. There may be redness, itching, swelling, and crusting.

手术和其他治疗方法
刮除法：先使用一种称为刮匙的设备来刮掉受损的细胞。刮除之后可以进行电外科手术，及用电刀切割和破坏受影响的组织。该过程需要局部麻醉。副作用可能包括感染，瘢痕形成和治疗部位皮肤颜色变化。
手术切除：当AK是一个厚的角质丘疹，或怀疑有更深的侵袭并且需要进行组织病理学诊断时，应予以切除。虽然这种方法很少用于AK治疗。
Surgical and other procedures: 
Scraping (curettage). In this procedure, your surgeon uses a device called a curet to scrape off damaged cells. Scraping may be followed by electrosurgery, in which the doctor uses a pencil-shaped instrument to cut and destroy the affected tissue with an electric current. This procedure requires a local anesthetic. Side effects may include infection, scarring and changes in skin coloration at the site of treatment.
Surgical excision: Excision should be reserved for cases when the AK is a thick, horny papule, or when deeper invasion is suspected and histopathologic diagnosis is necessary. It is a rarely utilized technique for AK treatment.
磨皮术：可用于治疗多发AK病变的大面积。该过程涉及使用手持式仪器“打磨”皮肤，去除表皮的角质层。使用高速旋转的金刚石棱钻或钢丝刷。
Dermabrasion -Dermabrasion is useful in the treatment of large areas with multiple AK lesions. The process involves using a hand-held instrument to "sand" the skin, removing the stratum corneum layer of the epidermis. Diamond fraises or wire brushes revolving at high speeds are used.
激光治疗：可使用二氧化碳（CO2）或Er：YAG激光。有时与计算机扫描技术结合使用。激光疗法尚未得到广泛研究，但目前的证据表明，它可能对涉及多种AKs药物治疗后复发的病例或位于美容敏感位置（如面部）的AK有效。二氧化碳激光被推荐用于广泛的光化性唇炎。
Laser therapy- using carbon dioxide (CO2) or erbium:yttrium aluminum garnet (Er:YAG) lasers is a treatment approach being utilized with increased frequency, and sometimes in conjunction with computer scanning technology. Laser therapy has not been extensively studied, but current evidence suggests it may be effective in cases involving multiple AKs refractive to medical therapy, or AKs located in cosmetically sensitive locations such as the face.The CO2 laser has been recommended for extensive actinic cheilitis.
光动力疗法:AKs是光动力疗法，包括局部5-氨基乙酰丙酸（5-ALA，艾拉）光动力治疗的最常见适应症之一。
治疗前需要对皮损进行预处理病变，包括使用真皮刮匙刮除鳞屑和结痂。将一层厚厚的5-ALA凝胶涂在病变部位和病变周围的一小块区域，然后用闭塞敷料覆盖并放置一段时间。在此期间，光敏剂积聚在AK病变内的靶细胞中。然后移除敷料并用特定波长的光处理病变。
已经研究了使用不同光敏剂，敷药时间，光源和预处理方案的多种治疗方案，并且表明更长的敷药时间导致更高的病变清除率。光动力疗法越来越受欢迎。研究发现它在治疗3个月后具有更高的完全清除病变的可能性，并且有更好的美容效果。光动力疗法特别在多个AK病变，以及大范围病变的治疗中有效。
Photodynamic therapy
AKs are one of the most common dermatologic lesions for which photodynamic therapy, including topical  5-aminolevulinic acid (5-ALA), is indicated.
Treatment begins with preparation of the lesion, which includes scraping away scales and crusts using a dermal curette. A thick layer of topical 5-ALA gel is applied to the lesion and a small area surrounding the lesion, which is then covered with an occlusive dressing and left for a period of time. During this time the photosensitizer accumulates in the target cells within the AK lesion. The dressings are then removed and the lesion is treated with light at a specified wavelength.
Multiple treatment regimens using different photosensitizers, incubation times, light sources, and pretreatment regimens have been studied and suggest that longer incubation times lead to higher rates of lesion clearance.Photodynamic therapy is gaining in popularity. It has been found to have a higher likelihood of achieving complete lesion clearance at 3 months and seems to result in superior cosmetic outcomes. Photodynamic therapy can be particularly effective in treating areas with multiple AK lesions.

以下是1例面部多发AK患者，经我团队3次光动力治疗后皮损明显消失：

Here is a case with multiple AK lesions on the face. After 3 sessions of PDT, most of her lesions dissapeared.

张江林教授在皮肤良恶性肿瘤的外科治疗方面有丰富的经验。得了皮肤肿瘤，莫惊慌，张江林教授团队为您保驾护航！

Professor  Jianglin Zhang is highly experienced in the surgical treatment of  benign and malignant skin growth. If you have a skin growth, don't  panic！Prof Zhang's team can help you get rid of it!