What is the appropriate use of sunscreen for infants and children?
EVIDENCE-BASED ANSWER
循证回答
英文原文
The risk and benefits of sunscreen use for children under the age of 6 months are unknown. To avoid sunburn, infants should be kept out of direct sunlight and be covered with protective clothing (strength of recommendation [SOR]: C, expert opinion). For children aged >6 months, a liberal amount of waterresistant, childsafe, broadspectrum sunscreen (protecting from both UVA and UVB), with SPF ≥15 should be rubbed well into all exposed skin before going outside (SOR: B, casecontrol and extrapolation of studies). Effectiveness may be increased if sunscreen is applied 30 minutes before exposure and reapplied every 2 hours, particularly if swimming(SOR: C, expert opinion). Tightly woven protective clothing, a widebrimmed cap, and eye protection should also be used whenever possible.Sunscreen effectively prevents burning due to sun exposure (SOR: A, randomized controlled trials). Sunburn early in life is a marker for increased risk of skin cancer in adulthood (SOR: B, casecontrol studies); however, evidence is insufficient that sunscreens lower skin cancer risk, as they also allow increased sun exposure. Reactions to sunscreens are generally limited to skin irritation from the active ingredients or vehicles (SOR: B, extrapolation from studies in adults).
对应中文
对于6个月以下的儿童使用防晒霜的风险和益处尚不清楚。为了避免晒伤，婴儿应该避免阳光直射，并穿上防晒衣（建议强度[SOR]：C，专家意见）。对于>6个月的儿童，应该使用防水、儿童安全的广谱防晒霜（同时保护UVA和UVB）、且SPF≥15的防晒霜，且在外出之前应该仔细地涂抹到所有可能暴露在阳光中的皮肤上（SOR：B，病例对照和研究推断）。如果在暴露前30分钟涂抹防晒霜并每隔2小时重复涂抹防晒霜，效果可能会提高，特别是在游泳时（SOR：C，专家意见）。在可能的情况下，还应使用编织紧密的防护服、宽边帽和护目镜。防晒霜能有效地防止因日晒造成的灼伤（SOR：A，随机对照试验）。早年晒伤是增加儿童患皮肤癌风险的危险因素（SOR:B，病例对照研究）；然而，防晒霜降低皮肤癌风险的证据还不够充分，因为它们也会增加阳光照射。对防晒霜的反应通常仅限于活性成分或载体对皮肤的刺激（SOR:B，来自成人研究的推断）。【小绛解读：“建议强度”，英文strength of recommendation （SOR），指临床上常用的证据等级分类，是基于外部（医学）证据的数量、质量、性质和一致性的综合标记，通常是字母等级(A、B或C)，由A至C，等级降低】
Discuss with parents the pitfalls of sunscreen use: insufficient application and risk of overexposure
与家长讨论使用防晒霜的陷阱：涂抹不足和过度暴露的风险
英文原文
Solar ultraviolet (UV) rays are grouped into 2 wavelengths: UVB (290–320 nm) causes acute inflammation, pain and erythema of sunburn; UVA (320–400 nm) is implicated in longterm damage to the skin, including photoaging and skin cancer, following carcinogenic induction by UVB.Sun protection factor (SPF) refers to the dose of UVB required to produce erythema in protected skin vs unprotected skin.UVA protection is offered in broad-spectrum sunscreens, but is not reflected by the SPF.
对应中文
太阳紫外线（UV）分为两种波长：UVB（290–320 nm）引起急性炎症、疼痛和晒伤红斑；UVA（320–400nm）会对皮肤造成长期损害，包括光老化和皮肤癌。防晒因子（SPF）是指在受保护皮肤和未受保护皮肤上产生红斑所需的UVB剂量。广谱防晒霜供防晒，但防晒效果不能反映在SPF数值中。
英文原文
SPF-15 is considered by experts to be adequate to prevent sunburn, assuming use of a 2 mg/cm2 layer of sunscreen (typically, 30 cc for an average adult). However, observations suggest people apply less than half that.2 Most experts recommend reapplication every 2 to 3 hours, though the quantity of sunscreen applied may be more important. A paired, splitbody study of children receiving supervised single vs multiple applications of SPF-25 sunscreen to randomly assigned lateral halves of their bodies found protection to be equal for 6 hours of direct sunlight exposure. When the study was repeated with 8 hours of exposure, half the children developed mild erythema on the side with 1 application.
对应中文
专家认为SPF15足以防止晒伤，假设使用2mg/cm²的防晒霜(一般情况下，普通成年人的防晒霜含量为30毫升)。然而，观察表明，人们涂抹的防晒霜还不到这个数字的一半。大多数专家建议每隔2到3小时涂抹一次，尽管防晒霜的涂抹数量可能更重要。一项配对的分体研究发现，在6小时的直射阳光下，接受SPF25防晒霜单次涂抹和多次涂抹防晒霜的儿童身体侧半部随机分配的防晒霜的保护效果是相等的。这项研究对接受监督的单次防晒霜和多次涂抹防晒霜的儿童进行了配对研究。当重复这项研究8小时后，一半的孩子在1次涂抹的情况下出现了轻度红斑。
英文原文
Because of the causal link between exposure to solar UV radiation and skin cancers, experts believe that sunscreens protect the wearer against the development of skin cancer. Casecontrol studies demonstrate that sunburn in childhood raises the risk of melanotic and nonmelanotic skin cancers, particularly among those with fair skin.However, studies of sunscreen’s ability to prevent skin cancer are limited due to variability in use, sun exposure, and susceptibility factors. A randomized controlled trial in adults supports that daily sunscreen use reduces the risk of squamous cell carcinoma but not basal cell carcinoma (number needed to treat=884 for 4.5 years).
对应中文
由于暴露在太阳紫外线辐射下与皮肤癌之间存在因果联系，专家认为防晒霜可以保护涂抹者免受皮肤癌的侵袭。病例对照研究表明，儿童时期的晒伤会增加患黑色素性和非黑色性皮肤癌的风险，特别是在那些皮肤白皙的人中。然而，由于使用、阳光照射和易受性因素的差异，对防晒霜预防皮肤癌能力的研究受到限制。一项针对成年人的随机对照试验表明，每天使用防晒霜可以降低鳞状细胞癌的风险，但不会降低基底细胞癌的风险（需要治疗的人数=884，持续4.5年）。
英文原文
Sunscreen permits longer sun exposure and may increase the development of nevi, known to be associated with malignant melanoma risk.A retrospective study of 6- to 7-year-old children found that sunscreen use correlated with an increasing number of nevi, though wearing clothing to cover skin while in the sun was protective.However, a randomized controlled trial (RCT) demonstrated that regular use of broadspectrum sunscreen in young schoolaged children resulted in fewer melanotic nevi compared with controls.A meta-analysis of 18 observational studies did not show an association between sunscreen use and melanoma incidence.
对应中文
防晒霜允许更长的时间暴露在阳光下，并可能增加痣的发生，已知这与恶性黑色素瘤的风险有关。一项对6至7岁儿童的回顾性研究发现，使用防晒霜与痣数量的增加有关，尽管在阳光下穿衣服遮盖皮肤是有保护作用的。然而，一项随机对照试验(RCT)表明，与对照组相比，学龄儿童经常使用广谱防晒霜导致黑色素痣较少。对18项观察性研究进行的荟萃分析显示，使用防晒霜与黑色素瘤发病率之间没有关联。
英文原文
Sunscreens can cause skin irritation or allergic reaction to either the active ingredient or vehicle.A RCT of 603 adults found no allergic reactions to active sunscreen ingredients, though 19% of subjects had an irritant reaction or allergy to the base compounds.9 Because infants’ skin may have different absorptive characteristics from that of older children, the US Food and Drug Administration recommends avoiding sunscreen before 6 months of age. As research is lacking for this age group, and the risk of harm due to sunburn is real, it would be reasonably prudent to use sunscreen when physical protection from the sun is impossible, and to avoid ingredients that caused a previous reaction.
对应中文
防晒霜可引起皮肤刺激或对活性成分或媒介物的过敏反应。一项随机对照试验（RCT）在603名成年人中没有发现对活性防晒霜成分的过敏反应，但有19%的受试者对基质化合物有刺激性反应或过敏反应。由于婴儿皮肤的吸收特性可能与年龄较大的儿童不同，美国食品和药物管理局（FDA）建议在6个月前避免使用防晒霜。由于缺乏对这一年龄组的研究，而且晒伤造成伤害的风险是真实存在的，因此在不可能进行身体防晒的情况下，使用防晒霜是相当谨慎的，并且要避免导致先前反应的成分。
Recommendations from others
其他人的建议
英文原文
The Centers for Disease Control and Preventionand the American Academy of Pediatrics recommend protection from sun exposure for all children and adolescents, including regular and adequate use of broadspectrum sunscreen for children over 6 months, protective clothing, and sunglasses. The US Preventive Services Task Force reports that evidence is insufficient to recommend for or against counseling by primary care clinicians to prevent skin cancer.
对应中文
疾病控制和预防中心和美国儿科学会建议所有儿童和青少年避免暴露在阳光下，包括为6个月以上的儿童定期和充分使用广谱防晒霜、防护服和太阳镜。美国预防服务工作组报告说，证据不足以支持或反对初级护理临床医生为预防皮肤癌而提供的咨询。
REFERENCES
1.Meurer, L. N., et al. (2006). “Clinical inquiries. What is the appropriate use of sunscreen for infants and children?” J Fam Pract 55(5): 437, 440, 444.