Why do I get hives when I scratch an itch
Itchy skin with chronic hives: What is the cause?
Itchy skin is one of the main symptoms of chronic hives, along with raised patches, or welts, on the skin. The welts may be flesh-colored, pink, or red, depending on skin tone, with a paler spot in the middle.
Chronic hives is a distinct medical condition. For a person to have chronic hives, they must experience symptoms for at least
Many different medical conditions and triggers can lead to chronic hives. In some cases, doctors cannot identify the cause.
This article examines itchy skin and chronic hives, symptoms, causes, and how to treat them.
Itchy skin is a key symptom of chronic hives. The welts themselves may be itchy, and so might the area around them.
Itchiness can also be a precursor to the development of hives. For example, if a person is having an allergic reaction that is causing chronic hives, itchy skin may develop just before the welts do.
Some people with chronic hives have also have a type of fluid buildup under the skin known as angioedema. Angioedema may occur around the lips, eyes, genitals, hands, and feet, which may also cause tight or itchy skin. However, the
Itchy skin is not the only symptom of chronic hives. The others include:
- Welts: These typically appear as raised, itchy bumps on the skin that are pink, red, or flesh-colored, typically with a paler spot in the middle. Some people also call them wheals. Each one typically lasts
less than 24 hours without leaving any marks or scarring. - Angioedema: Some people with chronic hives also experience general swelling under the skin. This occurs due to fluid buildup. For 10% of people, angioedema is their main symptom.
- Secondary symptoms: Those who scratch or pick the welts may have additional symptoms, such as crusts or lesions. These could potentially result in scars.
For a person to meet the criteria for chronic hives, the symptoms must occur every day, or on most days, for a minimum of 6 weeks.
The welts may appear with distinct borders, but they can also cluster together, forming larger raised bumps. As the symptoms continue, they will come and go, possibly migrating around the body.
It is not always clear what causes a persons chronic hives. Some people have idiopathic hives, or chronic spontaneous urticaria (CSU), which means there is no identifiable cause.
Others have physical hives, or chronic inducible urticaria (CIndU), which means the hives reliably appear in response to specific triggers.
In either case, experts believe the mechanism behind chronic hives is an immune response. In the case of CSU, this may be an autoimmune response, meaning the body is targeting healthy cells by mistake. This triggers the release of histamine in the skin, which is a chemical that causes allergic reactions.
With CIndU, the immune system mistakenly perceives a substance or type of physical stimuli as a threat. This could include, but is not limited to:
- certain foods
- latex, or foods that contain substances similar to latex, such as kiwis, bananas, mangoes, and chestnuts
- physical touch, pressure, or friction from clothes or bags
- touching certain substances, animals, or plants
- hot or cold temperatures
- UV light from the sun, tanning beds, or other UV lamps
- medications, which could cause a reaction while taking the medication or potentially months or years later
- adrenaline from stress or exercise
- water or vibration, although this is rare
Infections resulting from specific bacteria, viruses, and parasites also have associations with chronic hives,
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It is possible that autoimmunity may be the cause of CSU, but scientists are still learning about this. Many people with CSU also have another autoimmune condition, suggesting a connection.
The most common autoimmune condition in people with CSU is hypothyroidism. This causes the thyroid gland in the neck to produce less thyroid hormone than it should. In an older 2012 study, 9.8% of people with CSU also had hypothyroidism.
Other autoimmune diseases with links to chronic hives include:
To diagnose chronic hives, doctors will perform a physical examination of the skin and then ask questions to try and determine the cause or trigger.
They may take a full medical history, looking at other conditions a person has, medications they take, and what they were doing when the hives first began. If a person is unsure, the doctor may suggest keeping a diary to track flare-ups and help identify possible causes.
If a doctor suspects CSU but a person has no other autoimmune conditions, they may order blood tests to look for signs of inflammation or autoimmunity. Allergy testing, such as skin prick testing, is typically not useful in these cases.
If doctors cannot quickly determine the cause of chronic hives, there are steps people can take to reduce discomfort. Try:
- wearing loose-fitting clothes
- opting for soft, natural materials, such as cotton
- keeping the body at a comfortable temperature
- using products on the skin that contain no irritants or common allergens, such as fragrances
- applying cold compresses to the skin welts unless cold appears to trigger them
- using over-the-counter anti-itch creams such as calamine lotion or antihistamine creams
- practicing relaxation or mindfulness techniques to help manage stress
If or when doctors do identify the cause, they may be able to provide a person with more tailored treatment. This could include antihistamine medications or other drugs, such as omalizumab (Xolair) or cyclosporin. To manage a severe flare-up, doctors may sometimes recommend a short course of corticosteroids.
If a person with an autoimmune disease has chronic hives, managing the underlying condition may help manage itchy skin.
According to the American Academy of Dermatology Association (AAD), about 50% of people recover from chronic hives within 1 year. Between 8090% of people will experience a reduction in symptoms within 5 years.
Chronic hives can reappear later on, but treatment can help manage them. Anyone who is concerned about recurring itchy skin and hives should speak with a doctor or dermatologist.
Itchy skin is a key symptom of chronic hives. The welts or wheals themselves are itchy, but itchiness can also occur in the surrounding area.
Doctors cannot always identify the cause, but several treatments and lifestyle changes can help relieve itchy skin with chronic hives, such as calamine lotion and antihistamines. Keeping a symptom diary can help with identifying triggers, which may enable people to reduce flare-ups.
Why Do We Scratch That Itch?
An itch can feel like a burn, an electric shock, or a crawling sensation. Its caused by stimulated nerve cells in the skin, which make you want to scratch the affected area.
If itching keeps you up at night, youre not alone.
Pruritus (aka itching) is a sensation we all experience daily, some of us more than others.
To ditch the itch, most of us resort to scratching to get relief. While this may feel oh so good, the moment you swipe at your skin, you trigger something known as the itch-scratch cycle.
An itch can feel like a burning sensation, a slightly electrical or periodic nonpainful sensation, or like something is crawling along the skin, says Dr. Melanie Palm, a board certified dermatologist and cosmetic surgeon.
Other than being extremely annoying at 2 a.m., an itch is a sensation caused by stimulation of nerve cells in the skin, which Dr. Adarsh Vijay Mudgil, founder of Mudgil Dermatology, says causes us to scratch.
If you think about it, scratching is a type of pain, yet we rely on it to get rid of an itch. When we scratch, Mudgil says we send low-level pain signals to the brain. These pain signals temporarily distract the brain from itch.
These pain signals also release serotonin in the brain, which he says feels really, really good.
But serotonin also resets the itch signal. In some cases, this can create a never-ending itch-scratch cycle.
To stop the constant need to scratch your scalp, back, or any other area of your body, you need to know why you get itchy in the first place.
Itching is caused by a complex interaction between cells of the skin and our nervous system, Mudgil says. Various cell types, proteins, and inflammatory mediators are involved.
Chemicals released in the skin send a message to the spine through nerves in the skin, then the spine communicates with the brain, and we become itchy, he adds.
One of the most common causes of itch on the skin is dry skin, which causes microfractures within the skin barrier, Palm says. When this happens, local inflammation from cell signaling occurs, and chemicals like histamine and kinins are released.
This causes tissue redness, swelling, and nerve irritation that are then interpreted by our body as itch, she explains.
Hives, irritants, or contact exposures on the skin can lead to a somewhat similar phenomenon as dry skin.
All of these conditions can cause skin irritation and swelling, and local release of irritating chemicals from cells, such as eosinophils and basophils, that irritate skin nerves and create an itching sensation, Palm says.
When to look for a cause
If youre not getting relief, or your itching is getting worse, it might be time to see your doctor.
During your appointment, its important to provide your doctor with a detailed history so they can get to the root cause of the itch. Palm says this includes information about any:
- medical conditions
- surgeries
- medications
- supplements
- topical skin care products
- occupational or recreational habits
- travel history
- food allergies
All of these are possible causes of an itch and should be systematically eliminated to identify the root cause of itch, Palm adds.
Itching is an inherently harassing and annoying sensation.
Our natural instinct is to eliminate it, and tactile stimulation (scratching) is a knee-jerk response for immediate, albeit temporary relief, Palm says.
But since this is temporary, were left with the irritating itch, and the itch-scratch cycle repeats itself yet again.
Sounds frustrating, right? Well, the good news is there are plenty of ways to stop scratching an itch.
If you know the source of the itch, choosing the right remedy can help speed up the healing process.
But if youre not sure whats causing it, a trip to your doctor or dermatologist is in order. Thats because theres no one-size-fits-all answer to stopping an itch or preventing scratching.
However, there are some general guidelines to follow when experiencing an itch.
Dont scratch, really
The best way to eliminate scratching, says Palm, is not to start.
As hard as that sounds, it can often amplify the intensity of the itch, and thats why its important to identify the underlying cause of the itch so that it can be treated, she explains.
Moisturize
If skin is dry, Palm says restoring the skin barrier with therapeutic moisturizers is extremely important and can provide fairly quick relief.
Find good anti-itch ingredients
To help soothe skin, look for anti-itch creams that contain:
- pramoxine
- capsaicin
- menthol
Try a topical corticosteroid
And if skin is inflamed, Palm says a topical corticosteroid or calcineurin inhibitor may be in order.
Use an antihistamine
Antihistamines are another popular option to relieve itching related to allergies and other skin conditions, such as hives.
Over-the-counter (OTC) oral antihistamines include nondrowsy products like Allegra and Claritin. You can also use Benadryl or Chlor-Trimeton, but proceed with caution. These products can cause drowsiness.
Apply a cold pack
Additionally, the American Academy of Dermatology (AAD) says applying a cold cloth or ice pack to the itchy area for 10 minutes or taking an oatmeal bath can help calm itchy skin.
Keep your hands busy
To avoid continuous itching, Palm says its important to occupy your hands, so youre not unconsciously scratching.
A stress ball, or activities that occupy the hands so that they cannot be tempted to scratch an itch, may be helpful for some, she adds.
Itchy skin and persistent scratching might be annoying, but its not always cause for concern.
That said, if home remedies and OTC products arent providing relief, or the need to scratch is increasing, you may want to talk to your doctor or a board certified dermatologist to find out whats causing you to itch.
With the proper diagnosis, youll be able to find an effective treatment.
