人為什么會發熱？附：孩子發燒，家長行動指南

兒童發熱，家長行動指南FEVER OVERVIEW 發燒概述

Fever is a normal response to a variety of conditions, the most common of which is infection. Fever occurs when the body's temperature is elevated as a result of the body's thermostat being reset to a higher-than-usual temperature.發熱是對各種疾病的正常反應，其中最常見的是感染。當身體的恒溫器被重置到比平常更高的溫度時，身體的溫度升高，就會發燒。

Nearly every child will develop a fever at some point. The challenge for caregivers is to know when to be concerned. This topic review will discuss the definition of a fever, how to accurately measure a child's temperature, how and when to treat fever, and signs and symptoms that require further evaluation.幾乎每個孩子都會在某個時候發燒。照顧者面臨的挑戰是知道什么時候該關心。本主題綜述將討論發燒的定義，如何準確測量兒童的體溫，如何和何時治療發熱，以及需要進一步評估的體征和癥狀。

FEVER DEFINITION 熱的定義

Because of the normal variation in body temperature, there is no single value that is defined as fever. In general, a fever means a temperature above 100.4°F (38°C). You might get slightly different numbers depending on how you take your child's temperature – oral (mouth), axillary (armpit), ear, forehead, or rectal.由于體溫的正常變化，沒有一個單獨的值被定義為發熱。一般來說，發燒意味著體溫高于100.4華氏度(38°C)。根據測量孩子體溫的方式，你可能會得到略微不同的數字——口腔、腋窩、耳朵、前額或直腸。

Axillary, ear, and forehead temperature measurements are easier to obtain than rectal or oral temperatures, but they are less accurate and may need to be confirmed rectally or orally in certain children.與直腸或口腔溫度相比，腋窩、耳和前額溫度測量更容易獲得，但它們不太準確，可能需要在某些兒童中通過直腸或口腔進行確認。

FEVER CAUSES 發燒的原因

Infection is the most common cause of fever in children. Common viral and bacterial illnesses are the most likely illnesses to cause fever. These include:感染是兒童發熱的最常見原因。常見的病毒性和細菌性疾病是最可能引起發熱的疾病。這些包括:

●Colds (see "Patient education: The common cold in children (Beyond the Basics)")感冒(見“病人教育:兒童普通感冒(基礎之外)”)

●Gastroenteritis (see "Patient education: Nausea and vomiting in infants and children (Beyond the Basics)")胃腸炎(見“患者教育:嬰兒和兒童的惡心和嘔吐(基礎知識之外)”)

●Ear infections (see "Patient education: Ear infections (otitis media) in children (Beyond the Basics)")耳感染(見“患者教育:兒童耳感染(中耳炎)(基礎之外)”)

●Croup (see "Patient education: Croup in infants and children (Beyond the Basics)")哮吼(見“患者教育:嬰幼兒哮吼(基礎以外)”)

●Bronchiolitis (see "Patient education: Bronchiolitis and RSV in infants and children (Beyond the Basics)")毛細支氣管炎(見“患者教育:嬰幼兒毛細支氣管炎和RSV(基礎之外)”)

●Urinary tract infections (see "Patient education: Urinary tract infections in children (Beyond the Basics)")尿路感染(見“患者教育:兒童尿路感染(基礎之外)”)

There is little or no scientific evidence to support the widespread belief that teething causes fever. Although it is difficult to disprove this notion completely, alternative causes of fever should always be sought and temperatures above 102°F (38.9°C) should never be attributed to teething.幾乎沒有科學證據支持出牙會導致發燒這一普遍觀點。雖然很難完全否定這一觀點，但發熱的其他原因應始終尋找，絕不應將102華氏度(38.9°C)以上的溫度歸因于出牙。

Bundling a child who is less than three months old in too many clothes or blankets can increase the child's temperature slightly. However, a rectal temperature of 101°F (38.5°C) or greater is not likely to be related to bundling and should be evaluated. (See 'Evaluation recommended' below.)給3個月以內的孩子裹上太多的衣服或毯子會使孩子的體溫略微升高。然而，101°F(38.5°C)或更高的直腸溫度不太可能與束帶相關，應該進行評估。(見下面的“建議評估”。)

Some childhood immunizations can cause fever. The timing of the fever varies, depending upon which vaccination was given. (See "Patient education: Vaccines for infants and children age 0 to 6 years (Beyond the Basics)".)一些兒童接種疫苗會引起發熱。發熱的時間因接種疫苗的種類而異。(見“患者教育:0 - 6歲嬰兒和兒童的疫苗接種(基礎之外)”。)

HOW DO I MEASURE MY CHILD'S TEMPERATURE?如何測量孩子的體溫?

Glass versus digital thermometers — Digital thermometers are inexpensive, widely available, and the most accurate way to measure temperature. A variety of styles are available.玻璃溫度計與數字溫度計的比較——數字溫度計價格低廉，廣泛使用，是測量溫度的最準確的方法。有多種款式可供選擇。

Glass thermometers that contain mercury are no longer readily available for purchase. The glass thermometers that are sold now contain a different material that is nontoxic when swallowed. If a glass thermometer contains a silver liquid, it may contain mercury, while those with liquids of other colors do not. If a digital or non-mercury-containing glass thermometer is not available, be sure to carefully "shake down" the glass thermometer before use. Instructions for disposing of thermometers that contain mercury are available online (www.epa.gov/mercury).含有水銀的玻璃溫度計不再容易買到?，F在出售的玻璃溫度計含有一種不同的材料，吞咽時無毒。如果玻璃溫度計中含有銀色液體，它可能含有水銀，而那些含有其他顏色液體的溫度計則沒有。如果沒有數字或不含汞的玻璃溫度計，請務必在使用前仔細“搖下”玻璃溫度計。處理含汞溫度計的說明可在網上獲取(www.epa.gov/mercury)。

Other types of thermometers are available, including plastic strip and pacifier thermometers. However, these are not as accurate as digital thermometers and are not recommended.其他類型的溫度計，包括塑料條和奶嘴溫度計。然而，這些沒有數字溫度計準確，不建議使用。

Where to measure temperature — The best way to measure a child's temperature depends upon several factors. For children who can hold a thermometer under the tongue using proper technique (usually children older than four or five years), temperature can be measured accurately in the mouth. For infants and children who cannot hold the thermometer under the tongue, temperature can be measured in the armpit. If the armpit temperature is over 99°F (37.2°C) and there is concern that the child is ill, a rectal temperature may be necessary. A rectal temperature is also appropriate for infants from birth to three months of age. In the hospital setting, a rectal temperature is usually obtained before making medical decisions (eg, whether to obtain laboratory tests).在哪里測量體溫——測量兒童體溫的最佳方法取決于幾個因素。對于能夠用適當的方法將體溫計放在舌下的兒童(通常是4、5歲以上的兒童)，可以準確地測量口腔內的溫度。對于不能將體溫計放在舌下的嬰幼兒，可以在腋下測量體溫。如果腋窩溫度超過99°F(37.2°C)，擔心孩子生病，可能需要測肛溫。從出生到3個月大的嬰兒的直腸溫度也是合適的。在醫院，通常在做出醫療決定(如是否進行實驗室檢查)之前測量直腸溫度。

Temperatures measured in the ear or on the forehead also are less accurate than temperatures measured rectally or orally and may need to be confirmed by one of these methods.在耳朵或前額測量的溫度也不如直腸或口腔測量的溫度準確，可能需要通過這些方法中的一種來確認。

It is not accurate to estimate a child's temperature by feeling the child's skin. This is called a tactile temperature, and it is highly dependent upon the temperature of the person who is feeling the child's skin.通過觸摸孩子的皮膚來估計孩子的體溫是不準確的。這被稱為觸覺溫度，它高度依賴于觸摸孩子皮膚的人的溫度。

How to measure temperature at specific sites如何測量特定地點的溫度

●Rectal temperature 直腸溫度

?The child or infant should lie down on their stomach across an adult's lap.兒童或嬰兒應俯臥在大人的膝蓋上。

?Apply a small amount of petroleum jelly (eg, Vaseline) to the end of the thermometer.在溫度計的末端涂上少量凡士林(如凡士林)。

?Gently insert the thermometer into the child's anus until the silver tip of the thermometer is not visible (1/4 to 1/2 inch inside the anus) (figure 1).輕輕地將體溫計插入孩子的肛門，直到看不到體溫計的銀尖端(肛門內1/4至1/2英寸)(圖1)。

?Hold the thermometer in place. A glass thermometer requires two minutes, while most digital thermometers need less than one minute.把溫度計放好。玻璃溫度計需要兩分鐘，而大多數數字溫度計需要不到一分鐘。

●Oral temperature 口腔溫度 – Do not measure the temperature in a child's mouth if they have consumed a hot or cold food or drink in the last 30 minutes.-不要測量兒童在過去30分鐘內進食熱或冷的食物或飲料后的口腔溫度。

?Clean the thermometer with cool water and soap. Rinse with water.用冷水和肥皂清洗溫度計。用清水沖洗。

?Place the tip of the thermometer under the child's tongue toward the back. Ask the child to hold the thermometer with their lips.將體溫計的尖端朝后放在孩子的舌下。讓孩子用嘴唇拿著體溫計。

?Keep the lips sealed around the thermometer. A glass thermometer requires approximately three minutes, while most digital thermometers need less than one minute.把溫度計封住。一個玻璃溫度計大約需要三分鐘，而大多數數字溫度計需要不到一分鐘。

●Armpit temperature 腋窩溫度

?Place the tip of the thermometer in the child's dry armpit.將體溫計的尖端放在孩子干燥的腋下。

?Hold the thermometer in place by holding the child's elbow against the chest for four to five minutes.將孩子的肘部貼在胸前4 ~ 5分鐘，保持體溫計的位置。

●Ear temperature 耳朵溫度 – Ear thermometers are not as accurate as rectal or oral thermometers. If the child has been outside on a cold day, wait 15 minutes before measuring the ear temperature. Ear tubes and ear infections do not affect the accuracy of an ear temperature.-耳測溫儀不如直腸或口腔測溫儀準確。如果孩子曾在寒冷的天氣外出，等待15分鐘后再測量耳朵的溫度。耳管和耳感染不影響耳溫的準確性。

?To measure temperature accurately in the ear, the caregiver must pull the child's outer ear backward before inserting the thermometer (figure 2).

為了準確測量耳內溫度，在插入體溫計之前，照顧者必須將孩子的外耳向后拉(圖2)。

?Hold the ear probe in the child's ear for approximately two seconds.將耳探器放在孩子的耳朵里大約兩秒鐘。

●Temporal artery temperature顳動脈溫度– The temperature of the temporal artery can be taken by a device that is run over the forehead and in front of the ear (contact) or one that takes the temperature without touching your child using an infrared sensor (noncontact). These devices are not as accurate as a rectal or oral temperature but may be used to screen for fever in children older than four years of age.-顳動脈的溫度可以通過覆蓋在額頭和耳前的設備來測量(接觸式)，也可以在不接觸孩子的情況下使用紅外傳感器測量(非接觸式)。這些設備不如直腸或口腔溫度準確，但可用于4歲以上兒童的發熱篩查。

SHOULD I TREAT MY CHILD'S FEVER?我應該治療我孩子的發燒嗎?

There are pros and cons of treating fever. Fever may play a role in fighting infection, but it can also make a child uncomfortable.治療發熱有利弊。發燒可能在對抗感染中發揮作用，但也可能使孩子感到不舒服。

The height of a child's fever is not always the best indicator of whether the child needs to be treated and/or evaluated. Instead, it is important to note how a child behaves and appears. Fever is usually accompanied by other symptoms. Some of these symptoms require evaluation by a health care provider, even if there is no fever. The table provides a list of some of these symptoms (table 1).兒童的發熱高度并不總是兒童是否需要治療和/或評估的最佳指標。相反，注意孩子的行為和外表是很重要的。發熱通常伴有其他癥狀。即使沒有發熱，其中一些癥狀也需要由衛生保健提供者進行評估。該表提供了其中一些癥狀的列表(表1)。

In most cases, a child with a fever can be observed and/or treated at home. However, it is important for caregivers to know when a child with a fever needs to be evaluated by a health care provider, when fever should be treated, and when it is reasonable to observe the child without treating the fever.在大多數情況下，發燒的兒童可以在家觀察和/或治療。然而，重要的是，照護者應了解什么時候發燒的兒童需要由衛生保健提供者進行評估，什么時候應該治療發熱，以及什么時候觀察兒童而不治療發熱是合理的。

The guidelines provided below are general guidelines that do not apply to every situation; caregivers who have questions or are concerned about their child should contact their child's health care provider for advice.以下提供的準則是一般性準則，并不適用于所有情況;有問題或擔心孩子的照護者應與孩子的衛生保健提供者聯系，尋求建議。

Evaluation recommended — A health care provider should be consulted in the following situations:建議評估——在下列情況下應咨詢衛生保健提供者:

●Infants who are less than three months of age who have a rectal temperature of 100.4°F (38°C) or greater, regardless of how the infant appears (eg, even well-appearing young infants should be evaluated). These patients should not receive fever medication (eg, acetaminophen) until they have consulted with their health care provider.3個月以下的嬰兒，直腸溫度≥100.4°F(38°C)，無論嬰兒外表如何(例如，即使是外觀良好的小嬰兒也應進行評估)。這些患者在咨詢醫務人員之前不應接受發熱藥物(如對乙酰氨基酚)治療。

●Children who are three months to three years who have a rectal temperature of 100.4°F (38°C) or greater for more than three days or who appear ill (eg, fussy, clingy, refusing to drink fluids).3個月至3歲的兒童，直腸溫度≥100.4華氏度(38°C)超過3天或出現疾病(如挑剔、黏人、拒絕喝水)。

●Children who are 3 to 36 months who have a rectal temperature of 102°F (38.9°C) or greater.直腸溫度≥102華氏度(38.9℃)的3 - 36個月兒童。

●Children of any age whose oral, rectal, tympanic membrane, or forehead temperature is 104°F (40°C) or greater or whose axillary temperature is 103°F (39.4°C) or greater.口腔、直腸、鼓膜或前額溫度≥104°F(40°C)或腋窩溫度≥103°F(39.4°C)的任何年齡兒童。

●Children of any age who have a febrile seizure. Febrile seizures are convulsions that occur when a child (between six months and six years of age) has a temperature greater than 100.4° F (38°C). (See "Patient education: Febrile seizures (Beyond the Basics)".)有熱性驚厥的任何年齡的兒童。熱性驚厥是兒童(6個月至6歲)體溫超過100.4華氏度(38℃)時發生的驚厥。(見“患者教育:熱性驚厥(基礎之外)”。)

●Children of any age who have recurrent fevers without any other symptoms for more than seven days, even if the fevers last only a few hours.任何年齡的兒童，在沒有任何其他癥狀的情況下反復發熱超過7天，即使發熱只持續幾個小時。

●Children of any age who have a fever and have a chronic medical problem such as heart disease, cancer, lupus, or sickle cell anemia.任何年齡的發燒和有慢性疾病如心臟病、癌癥、狼瘡或鐮狀細胞性貧血的兒童。

●Children who have a fever as well as a new skin rash.有發燒和新發皮疹的兒童。

Treatment recommended — Treatment of fever is recommended if a child has an underlying medical problem, including diseases of the heart, lung, brain, or nervous system. In children who have had febrile seizures in the past, treatment of fever has not been shown to prevent seizures but is still a reasonable precaution.建議治療——如果孩子有潛在的醫學問題，包括心臟、肺、腦或神經系統疾病，建議對發熱進行治療。對于既往有熱性驚厥發作的兒童，尚未證明發熱治療可預防驚厥發作，但仍是一種合理的預防措施。

Treatment of fever may be helpful if the child is uncomfortable, although it is not necessary.如果患兒不舒服，治療發熱可能是有幫助的，但這不是必要的。

Treatment not required — In most cases, it is not necessary to treat a child's fever. A child older than three months who has a rectal temperature less than 102°F (38.9°C) and who is otherwise healthy and acting normally does not require treatment for fever.不需要治療——在大多數情況下，不需要治療兒童的發熱。3個月以上、直腸溫度低于102華氏度(38.9℃)、其他方面健康且行為正常的兒童不需要發熱治療。

Caregivers who are unsure if their child's fever needs treatment should contact the child's health care provider. (See 'Evaluation recommended' above.)不確定孩子發熱是否需要治療的照護者應與孩子的衛生保健提供者聯系。(見上文“建議評估”。)

FEVER TREATMENT OPTIONS 發熱治療方案

Medications — The most effective way to treat fever is to use a medication such as acetaminophen (sample brand name: Tylenol) or ibuprofen (sample brand names: Advil, Motrin). These treatments can reduce the child's discomfort and lower the child's temperature by 2 to 3°F (1 to 1.5°C). Aspirin is not recommended for children under age 18 years due to concerns that it can cause a rare but serious illness known as Reye syndrome.藥物治療——治療發熱最有效的方法是使用對乙酰氨基酚(樣品品牌名稱:泰諾)或布洛芬(樣品品牌名稱:Advil, Motrin)等藥物。這些治療可減輕患兒的不適感，并將患兒體溫降低2 ~ 3°F(1 ~ 1.5°C)。阿司匹林不推薦給18歲以下的兒童，因為擔心它會導致一種罕見但嚴重的疾病，即瑞氏綜合征。

Acetaminophen may be given every four to six hours as needed but should not be given more than five times in a 24-hour period. Acetaminophen should not be used in children younger than three months of age without consultation with a health care provider. The dose of acetaminophen should be calculated based upon the child's weight (not age).對乙酰氨基酚可按需每4 ~ 6小時服用1次，但24小時內不得服用超過5次。在未咨詢醫務人員的情況下，對乙酰氨基酚不能用于3個月以下的兒童。對乙酰氨基酚的劑量應根據兒童的體重(而不是年齡)計算。

Ibuprofen may be given every six hours. Ibuprofen should not be used in children younger than six months of age. The dose of ibuprofen should be calculated based upon the child's weight (not age).布洛芬可以每6小時給藥一次。布洛芬不能用于小于6個月的兒童。布洛芬的劑量應根據兒童的體重(而不是年齡)計算。

Giving combinations of acetaminophen and ibuprofen or alternating acetaminophen and ibuprofen increases the chance of giving the wrong dose of one or the other of the medications and is not recommended routinely.聯合使用對乙酰氨基酚和布洛芬或交替使用對乙酰氨基酚和布洛芬會增加給其中一種或另一種藥物錯誤劑量的機會，不建議常規使用。

Fever-reducing medications should only be given as needed and discontinued once bothersome symptoms have resolved.退熱藥物只應按需用藥，并在煩人的癥狀消失后停用。

Increase fluids — Having fever can increase a child's risk of becoming dehydrated. To reduce this risk, caregivers should encourage their child to drink an adequate amount of fluids. Children with fever may not feel hungry, and it is not necessary to force them to eat. However, fluids such as milk (cow's or breast), formula, and water should be offered frequently. Older children may eat flavored gelatin, soup, or frozen popsicles. If the child is unwilling or unable to drink fluids for more than a few hours, the caregiver should consult the child's health care provider.增加液體——發燒會增加孩子脫水的風險。為了降低這種風險，看護人應鼓勵孩子喝足量的液體。發熱患兒可能不會感到饑餓，也沒有必要強迫其進食。然而，應經常提供牛奶(奶牛或母乳)、配方奶和水等液體。年齡較大的孩子可能會吃調味的明膠、湯或冷凍冰棍。如果孩子不愿意或不能喝液體超過幾個小時，看護人應咨詢孩子的衛生保健提供者。

Rest — Having a fever causes most children to feel tired and achy. During this time, caregivers should encourage their child to rest as much as the child wants. It is not necessary to force the child to sleep or rest if they begin to feel better. Children may return to school or other activities when the temperature has been normal for 24 hours.休息——發燒會使大多數孩子感到疲倦和疼痛。在此期間，看護人應該鼓勵孩子盡可能多地休息。如果孩子開始感覺好一些，沒有必要強迫他們睡覺或休息。當溫度正常24小時后，兒童可以返回學?；騾⒓悠渌顒?。

Sponging and baths — Sponging is not as effective as medications for fever and generally is not recommended. Alcohol should not be used for sponging because of the risk of toxicity if it is absorbed through the skin.用海綿擦浴和洗澡——用海綿擦浴不如用藥物治療發燒有效，一般不建議使用。酒精不能用在海綿上，因為如果它通過皮膚吸收會有中毒的風險。

參考文獻：Patient education: Fever in children (Beyond the Basics)，Uptodate,2024

翻譯：陳舟醫生