有一个不会停止的痒吗？皮肤发痒是最令人沮丧的感觉之一，尤其是当感觉无济于事时。更糟糕的是，皮肤发痒的原因有很多，包括一般的蚊虫叮咬以及荨麻疹和牛皮癣的干燥。虽然对于其中一些，非处方霜或软膏可能会起作用，但皮肤发痒背后的其他因素可能更难弄清楚。
Got an itch that won’t quit? Itchy skin is one of the most frustrating feelings, especially when it feels like nothing will help. Worse, itchy skin can happen for many reasons, including your average mosquito bite and dryness to hives and psoriasis. While for some of these, an over-the-counter cream or ointment may do the trick, other factors behind itchy skin can be trickier to figure out.
皮肤科医生 Hassan Galadari，医学博士分解了您可能会皮肤发痒的十个原因——以及您可以做些什么。
Dermatologist Hassan Galadari, MD breaks down ten reasons you might have itchy skin—and what you can do about it.
1. 干性皮肤
Dry Skin
原因：干性皮肤缺少皮肤屏障中的必需成分，如脂质和油脂。 “这暴露并允许增加被称为 C 神经纤维的神经末梢，它传递类似瘙痒的感觉，”加拉达里博士解释说。它们是温暖感觉背后的相同神经，比如燃烧。
What Causes It: Dry skin is missing essential components in the skin barrier, like lipids and oils. “This exposes and allows for the increase in nerve endings known as C nerve fibers, which transmit an itch-like sensation,” explains Dr. Galadari. They’re the same nerves behind sensations of warmth, like burning.
如何治疗：如何打败干燥的皮肤？试试保湿霜的魔力。 “它增加了皮肤上部的脂质屏障，减少了这些神经纤维的暴露，”加拉达里解释说。
How to Treat It: How to defeat dry skin? Try the magic of moisturizer. “It increases the lipid barrier on the upper part of the skin, decreasing the exposure of these nerve fibers,” explains Galadari.
2. 皮疹
Rash
引起它的原因：很多事情都会引起发痒的皮疹，但最常见的是荨麻疹和特应性皮炎。通常情况下，“组胺的释放会激活 C 神经纤维，”Galadari 说。
What Causes It: A number of things can cause itchy rashes, but the most common are hives and atopic dermatitis. Oftentimes, “there’s a release of histamine that activates the C nerve fibers,” says Galadari.
如何治疗：根据 Galadari 的说法，这在很大程度上取决于病因。大多数时候，抗组胺药或适当的卫生措施（例如用温和的清洁剂清洗该区域并涂抹润肤剂和非处方皮质类固醇乳膏）会有所帮助。但是，如果您的皮疹在几天内没有改善，请去看医生以获得具体的诊断和治疗计划。
How to Treat It: It depends largely on the cause, according to Galadari. Most of the time, an antihistamine or just proper hygiene—like washing the area with a gentle cleanser and applying emollients and over-the-counter corticosteroid creams—can help. But if your rash doesn’t improve within several days, see your doctor to get a specific diagnosis and treatment plan.
3.虫咬
Bug Bite
是什么原因造成的：很可能你一直受到夏季蚊虫叮咬的困扰。虽然蚊子不会覆盖很大的区域，但它会留下唾液，这会引起皮肤反应。从好的方面来说，“咬的痒是非常局部的，它看起来像一个肿块，”Galadari 说，很容易识别。
What Causes It: Odds are that you’ve been plagued by summertime mosquito bites. While a mosquito won’t cover a large area, it does leave behind its saliva, which provokes a skin reaction. On the bright side, “The itch of a bite is pretty localized, and it looks like a bump,” says Galadari, making it easy to identify.
如何治疗：首先，通过使用含有避蚊胺的面霜或乳液来防止被咬，Galadari 说，尤其是当你要在户外或温暖潮湿的天气中时。如果虫子感染了你，Galadari 建议服用抗组胺药并在该区域涂抹非处方氢化可的松乳膏。如果肿胀比发痒更痛苦——或者你呼吸困难，这可能表明过敏——尽快去看医生。
How to Treat It: First, prevent bites by wearing creams or lotions that contain DEET, says Galadari, especially if you’re going to be outside or in warm, humid weather. If a bug gets you anyway, Galadari recommends taking an antihistamine and applying an over-the-counter hydrocortisone cream to the area. If the swelling is more painful than itchy—or you have trouble breathing, which can indicate an allergy—see a doctor ASAP.
4. 湿疹或牛皮癣
Eczema or Psoriasis
导致它的原因：湿疹和牛皮癣都会引起发痒的感觉，但它们在您的皮肤上看起来完全不同。 “湿疹始于皮肤干燥、发痒，”加拉达里说。 “反复抓挠可能会导致可能的感染，并且该区域看起来渗出液和粗糙。”另一方面，牛皮癣在皮肤上表现为银色的鳞状斑块，并且与湿疹不同，它并不总是发痒。
What Causes It: Both eczema and psoriasis can cause an itchy feeling, but they look completely different on your skin. “Eczema starts as dry skin that’s itchy,” says Galadari. “The repeated scratching may cause possible infection and the area appears oozing and rough.” Psorasis, on the other hand, appears as silvery, scaly plaque on the skin, and, unlike eczema, doesn’t always itch.
如何治疗：如果您怀疑自己患有任何一种皮肤病，请访问您的皮肤以获得明确的诊断。只有这样，您才能得到适当的治疗——并缓解瘙痒。
How to Treat It: If you suspect you have either skin disease, visit your derm for a definitive diagnosis. Only then will you be able to get the proper treatment—and relief from the itchiness.
5.接触性皮炎
Contact Dermatitis
是什么原因造成的：呃，过敏。 “当患者遇到过敏原时会发生接触性皮炎，”Galadari 解释说。 “这可以是任何东西，从镍等金属到染发剂甚至皮革等日常材料。”
What Causes It: Ugh, allergies. “Contact dermatitis occurs when a patient encounters an allergen,” explains Galadari. “This can be anything from metals, such as nickel, to everyday materials such as hair dye or even leather.”
如何治疗：如果您知道可能是什么物质引起的，那么以后要注意避免这种情况。如果您仍然不确定，请去看医生。 “医生可能会使用一种称为贴片测试的方法来准确了解您对什么过敏，”加拉达里说。
How to Treat It: If you know what substance may have caused it, then take care to avoid that in the future. If you’re still not sure, go to your doctor. “The doctor may use a method called patch-testing to learn exactly what it is you’re allergic to,” says Galadari.
6. 荨麻疹
Hives
导致它的原因：当您的皮肤生气并激起免疫系统的反应时，就会出现那些似乎无处不在的发痒、红色或白色斑点。某些食物、药物、感染甚至温度的突然变化都可能引发荨麻疹。
What Causes It: Those itchy, red or white splotches that seem to appear out of nowhere occur when your skin is angry and instigates a reaction from your immune system. Anything from certain foods, medications, infections and even sudden changes in temperature can trigger a flare of hives.
如何治疗：由于荨麻疹是一种免疫反应，非处方抗组胺药是最好的选择。但是，如果您发现嘴唇和喉咙肿胀或荨麻疹持续时间超过一周，请看您的皮肤科医生。
How to Treat It: Since hives are an immune reaction, over-the-counter antihistamines are your best bet. But if you notice any swelling of the lips and throat or your hives last longer than a week, see your derm.
7. 某些药物
Certain Medications
导致它的原因：“任何导致干燥的药物都可能导致瘙痒，”Galadari 说。这可能涉及任何东西，从降低胆固醇的他汀类药物到异维A酸，一种可以对皮肤产生干燥作用的抗痤疮成分。
What Causes It: “Any medication that causes dryness may cause itchiness,” says Galadari. That could involve anything from statins, which lower cholesterol, to isotretinoin, an anti-acne ingredient that can have a drying effect on skin.
如何对待它：明智和滋润。 Galadari 说，确保你经常这样做。如果瘙痒难以忍受，请去看医生，医生可能需要调整药物剂量。
How to Treat It: Be wise and moisturize. Make sure you’re doing so regularly, says Galadari. If the itchiness is unbearable, see your doctor, who may need to adjust the dosage of your medications.
8. 怀孕
Pregnancy
导致它的原因：“荷尔蒙的变化会导致瘙痒，皮肤的拉伸也是如此，”Galadari 说。有时，怀孕期间的内部变化（如肝脏中的变化）也可能会加剧它。
What Causes It: “Changes in the hormones cause itchiness, as does the stretching of the skin,” says Galadari. Sometimes, internal changes during pregnancy (like those in the liver) may exacerbate it, too.
如何治疗：某些药物可能有助于缓解怀孕期间的瘙痒，但具体取决于引起瘙痒的原因。去看医生以获得确诊。
How to Treat It: Certain medications may help with itchiness during pregnancy, but they depend on what, exactly, is causing it. Visit your doctor to get a confirmed diagnosis.
9. 神经系统问题
Nervous System Issues
引起它的原因：由于瘙痒是由 C 神经纤维介导的，C 神经纤维是神经系统的一部分，任何扰乱神经系统的东西都会导致皮肤发痒。
What Causes It: Since itchiness is mediated by the C nerve fibers—which are part of your nervous system—anything that messes with your nervous system can lead to itchy skin.
如何治疗：根据 Galadari 的说法，外用辣椒素乳膏会有所帮助。如果情况更严重，“也可以使用其他药物来帮助减少神经活动，”他说。
How to Treat It: A topical capsaicin cream can help, according to Galadari. If it’s more severe, “Other medications may also be used to help decrease nerve activity,” he says.
10.心理原因
Psychological Causes
导致它的原因：仅仅考虑你的皮肤有多痒肯定会让它变得更糟，因为大脑与那些引起瘙痒的神经纤维相连。另外，“还有一些情况，例如强迫症，患者有一种无法解释的强迫性抓挠，”Galadari 说。 “这会加剧瘙痒并使情况变得更糟。”
What Causes It: Just thinking about how itchy your skin is can definitely make it worse, since the brain is connected to those nerve fibers that cause itchiness. Plus, “There are also conditions such as OCD, in which a patient has an unexplained compulsion to scratch,” says Galadari. “That can exacerbate itchiness and make matters worse.”
如何治疗：打破痒-抓的循环——无论是覆盖发痒的区域，使其难以抓挠，甚至保持指甲超短——是关键。对于强迫症等心理健康原因，认知行为疗法和药物也可能有所帮助。
How to Treat It: Breaking the itch-scratch cycle—whether by covering the itchy area so it’s difficult to scratch or even keeping your nails super short—is key. Cognitive behavioral therapy may also help, as can medications, in the case of mental health causes like OCD.
