Are hives contagious by touch
Are Hives Contagious?
Hives arent contagious, meaning you wont develop them on your skin by touching hives on another person. However, the trigger causing this skin reaction can be contagious.
Hives also referred to as urticaria are welts on the skin and are a type of itchy rash. They may be red or skin-colored, though hives on darker skin may be harder to see.
Hives can appear on any body part and are often triggered by an allergic reaction. If you press a hive, the center of the bump will turn pale.
Other causes of hives that are contagious are:
Although allergies can trigger hives, other things can also cause them. Understanding the cause can help to address ways to prevent this reaction and avoid the spread of hives.
Allergic hives
Contact with an allergen is the most common cause of hives. Allergic hives arent contagious.
Common allergens that can trigger hives are:
Infection-induced hives
Some viral and bacterial can cause hives. Examples of these conditions include:
These types of hives themselves arent contagious, but if the condition that causes them spreads to you, you could also develop hives.
These infections can spread through:
- airborne germs from sneezing and coughing
- poor hygiene
- sharing eating utensils
- direct contact with the saliva of an ill person
- contact with stool
Youre at more risk of developing an infection:
Environmental hives
Overexposure to the sun, cold, or water can cause physical hives. Body heat from physical activity can also cause a reaction. These can also be triggered by stress.
In addition, you may get hives simply from pressure on the skin, such as from clothes that are too tight.
Chronic hives
If you have chronic hives or chronic urticaria welts appear for up to six weeks at a time. In more severe cases, chronic hives can last for years.
About 1.4% of all people experience chronic hives, more commonly males than females. There is often an underlying condition that is triggering chronic hives, but sometimes there is no obvious cause.
Through lifestyle changes and precautions, you can help to prevent hive reactions. But this depends on whats causing the hives.
If you have a known allergy, you can do the following to prevent hives:
- Avoid eating foods or other substances you are allergic to.
- Carry an EpiPen in case of allergic emergencies.
- Take any allergy medicines as prescribed, but consult your doctor to find alternatives if the medicines themselves contain allergens.
- Avoid using harsh soaps that could cause irritation.
- Avoid wearing tight clothing.
- Wear protective clothing in cold weather or sun exposure.
- Do not swim alone in cold water.
Contagious bacteria can also cause conditions that trigger hives. Here are a few tips you
- Wash your hands regularly.
- Practice good hygiene.
- Get vaccinated for preventable infections.
- Limit contact with people who are sick or exhibit hives.
Hives are a kind of itchy rash characterized by welts on the skin. It is usually caused by allergies but can have other causes.
Hives themselves are not contagious, but their cause could be. For example, if you have hives caused by a virus, a person can contract the virus and also develop hives.
The treatment and prevention strategies for hives depend on the underlying cause.
Hives: Pictures, Causes, and How to Treat Them
Hives typically occur as an allergic response to something in your environment or something you ate. But they may sometimes happen because of an underlying health issue.
Hives, also known as urticaria, are itchy, raised welts that are found on the skin. Theyre usually red, pink, or flesh colored on lighter skin and may be flesh colored or slightly lighter or darker than your skin tone on brown or black skin.
Sometimes they sting or hurt. In most cases, hives are caused by an allergic reaction to a medication or food or are a reaction to an irritant in the environment.
In many cases, hives are an acute (temporary) problem that may be alleviated with allergy medications. Most rashes go away on their own. However, chronic (ongoing) cases, as well as hives accompanied by a severe allergic reaction, are larger medical concerns.
Hives are usually caused by an
In some people, histamines can cause swelling, itching, and many of the symptoms that are experienced with hives. In terms of allergens, hives can be
Hives might also be caused by circumstances besides allergies. Its not uncommon for people to experience hives as the result of stress, tight clothes, exercise, illnesses, or infections.
Its also possible to develop hives as the result of excessive exposure to hot or cold temperatures or from irritation due to excessive sweating. Because there are several potential triggers, many times the actual cause of hives cant be determined.
People who are known to have allergies are more likely to get hives. You may also be at risk of developing hives if youre taking medication or if youre unknowingly exposed to things you may be allergic to, such as food or pollen. If youre already ill with an infection or a health condition, you may be more vulnerable to developing hives.
The most noticeable symptom of hives is the welts that appear on the skin. Welts may be red but can also be the same color as your skin. They can be small and round, ring-shaped, or large and of random shape. Hives are itchy, and they tend to appear in batches on the affected part of the body. They can grow larger, change shape, and spread.
Hives may disappear or reappear over the course of the outbreak. Individual hives welts can last anywhere from
Hives can occur in a variety of places on the body. Call 911 or get medical attention immediately if you develop a hives outbreak around your throat or on your tongue or have trouble breathing along with hives.
Hives can occur in response to an allergic reaction or may not have an identifiable cause.
Allergic reactions
The most common causes of hives are allergic reactions. These can be caused by any allergen you might be sensitive to, including:
- foods (such as nuts, milk, and eggs)
- pet dander
- pollen
- dust mites
- insect bites or stings
- medications (primarily antibiotics, cancer drugs, or ibuprofen)
Mild cases of hives caused by allergies are typically treated with long- or short-term allergy medications and avoidance of the trigger.
Anaphylaxis
Anaphylaxis is a severe, life threatening allergic reaction. In this condition, hives are often
Chronic hives
Chronic hives are ongoing cases that dont necessarily have an identifiable cause. Also called chronic urticaria, this condition is marked by recurring hives that can interfere with your daily life. Chronic cases
You may suspect chronic hives if you have welts that dont go away within 6 weeks. While not life threatening, this form of hives can be uncomfortable and difficult to treat. Chronic hives may also be a symptom of an
- an autoimmune disorder
- celiac disease
- lupus
- type 1 diabetes
- rheumatoid arthritis
- thyroid disease
Dermatographism
This form of acute hives is considered mild. Excessive scratching or continuous pressure on the skin causes it. Dermatographism usually clears up on its own in a short period of time without treatment.
Temperature-induced hives
Sometimes changes in temperature can induce hives in people who are sensitive to such changes. Cold-induced hives may occur from cold water or air exposure, while body heat from physical activity may cause exercise-induced hives. Exposure to sunlight or tanning beds may also bring about solar hives in some people.
Infection-induced hives
Both viral and bacterial infections can cause hives. Common bacterial infections causing hives include urinary tract infections and strep throat. Viruses that cause infectious mononucleosis (mono), hepatitis, and colds often cause hives.
The first step in getting treatment is to figure out if you actually have hives. In most cases, a doctor will be able to determine if you have hives from a physical exam. Your skin will show signs of the welts that are linked with hives.
A doctor may also perform blood tests or skin tests to find out what may have caused your hives especially if your hives were the result of an allergic reaction.
You may not need prescription treatment if youre experiencing a mild case of hives not related to allergies or other health conditions. In these circumstances, a doctor might suggest that you find temporary relief by:
Anaphylaxis is a medical emergency that needs to be treated immediately by a physician. If you think you may be experiencing anaphylaxis, contact 911 or your local emergency services.
Simple changes to your lifestyle may be able to help you prevent hives from reoccurring in the future. If you have allergies and you know which substances are likely to cause an allergic reaction, a doctor will suggest that you avoid any possible exposure to these factors. Allergy shots are another option that may help you reduce the risk of experiencing hives again.
Avoid being in high humidity areas or wearing tight clothing if you have recently had a hives outbreak.
Below are some of the most commonly asked questions about hives.
Are hives contagious?
No, hives are not contagious and cant spread from one person to another.
Do hives mean Im allergic to something?
In many cases, hives are the result of an allergic reaction to something you have been exposed to, such as certain medications or pollen. It could also be caused by an infection, stress, or wearing clothes that are too tight. If you have hives that persist for more than a few days, contact a doctor to see if an allergy test is needed to determine the cause of your symptoms.
How long do hives last?
A hives outbreak can last anywhere from
Are there any home remedies for hives?
Yes, there are several home remedies that may help alleviate the symptoms of hives. Taking an antihistamine is one option, as well as taking a cool or lukewarm bath with colloidal oatmeal or baking soda. Avoid hot water, as this may aggravate the hives. Also, try to avoid any potential irritants or allergens that may have caused the hives in the first place.
Although hives can be itchy and uncomfortable, usually theyre not severe and will disappear after a period of time. However, be aware that as some hives go away, new ones may pop up.
Mild cases of hives are considered harmless. Hives can be dangerous if you are having a serious allergic reaction and your throat is swelling. Prompt treatment for a severe case of hives is important for a good outlook.
Hives
When you have hives (also known as urticaria), you have an itchy rash caused by tiny amounts of fluid that leak from blood vessels just under the skin surface.
A trigger causes cells in the skin to release chemicals such as histamine. The chemicals cause fluid to leak from tiny blood vessels under the skin surface. The fluid pools to form weals. The chemicals also cause the blood vessels to open wide (dilate) which causes the flare around the weals. It is not known what the trigger is in about half of cases.
Hives can be triggered by a number of different physical causes. The reason why a rash appears in affected people is not clear. The physical stimulus somehow causes a release of histamine and other chemicals, which causes the rash.
Some known triggers include:
A physical stimulus. Where this is the case the condition is called inducible urticaria. In this type of hives, a rash appears when the skin is physically stimulated (for example, by heat, cold or pressure on the skin).
Allergies - for example:
Food allergies such as allergies to nuts, strawberries, citrus fruit, egg, food additives, spices, chocolate, or shellfish. Sometimes you can develop an allergy to a food even if you have eaten it without any problem many times before.
Allergies to insect bites and stings.
Allergies to medicines such as penicillin, aspirin, anti-inflammatory painkillers, etc.
A viral infection such as the common cold or flu can trigger an urticarial rash in some people. (You react to the virus.) A mild viral infection which causes few other symptoms is probably a common trigger of an urticarial rash that develops without an apparent cause.
Skin contact with some substances causes a local area of contact hives in some people. For example, chemicals, latex, cosmetics, plants including pine trees, ointments, nettle stings, etc.
Pine tree contact:
Contact urticaria: pine tree rash
Hives can be classed as follows:
Acute - if it develops suddenly and lasts less than six weeks. Most cases last 24-48 hours. In some cases the rash only lasts a few hours. About 1 in 6 people will have at least one bout of hives in their lives. It can affect anyone at any age. Some people have recurring bouts of acute hives.
Chronic - if it persists longer than six weeks. This is uncommon.
Physical causes can result in repeated episodes of acute hives, or a persisting long-term condition.
The main types of inducible urticaria include the following:
Dermatographism
By R1carver, CC BY-SA 3.0, via Wikimedia Commons
Dermatographism (also known as dermographism and dermatographia) means skin writing. People with this condition develop the rash on areas of skin that have been firmly stroked. (Because of this, you could 'write' on someone's skin by applying firm pressure with a finger or other object. The rash follows the line of the writing on the skin.)
The affected area of skin is usually very itchy but in some mild cases it does not itch much. Although any part of the skin can be affected, the palms, soles of the feet, genital skin and scalp are less commonly affected.
Dermatographism is more prone to occur when you are hot. For example, it may develop more easily when you rub yourself firmly with a towel after a hot shower. The rash tends to last less than an hour. In many cases the pressure needed to be applied to cause the rash is quite firm. However, some people develop dermatographism with just light pressure.
Up to 1 in 20 people will develop dermatographism at some stage of life. It most commonly first develops in early adult life. In most cases, the condition tends to improve gradually over a few years and it goes or becomes less severe. However, in some cases the condition remains troublesome for many years.
Cholinergic hives
Cholinergic hives are quite common. The condition is caused by sweating and is sometimes called heat bumps. The hives rash is quite distinct as the weals are very small (2-3 mm) with a red flare around each one.
The rash appears within a few minutes of sweating and tends to be worst on the chest, back and arms. The rash lasts from 30 minutes to an hour or more before fading away. Some people become slightly wheezy and short of breath for the duration of the rash.
The sweating that triggers the rash may be due to exercise, heat, high temperature (fever), emotion or eating spicy food. It can be a real nuisance when trying to exercise. In severe cases, hundreds of tiny weals develop when you run or do other types of exercise. Sometimes the tiny weals join together to form larger ones.
Cholinergic hives most commonly first develop in early adult life. In many cases the condition tends to improve after a few years and it goes or becomes less severe. However, in some cases the condition remains troublesome for many years.
Cold hives
Cold hives are quite an uncommon condition. An urticarial rash develops after being exposed to cold, including rain, cold winds and cold water. It may be the cold that triggers the rash, or the re-warming of the skin after coming in from the cold.
The rash affects the chilled parts of the skin. If a large area of skin has been chilled, the rash can be very extensive. For example, swimming in cold water may cause a widespread and severe rash over most of the body that can make you dizzy and faint. (For this reason, if you are known to develop cold hives, you should never go swimming alone.)
Delayed pressure hives
Delayed pressure hives are uncommon. The condition can develop alone but it commonly affects people who also have chronic hives. In this type of hives the rash develops 4-6 hours after the affected area of skin has had deep prolonged pressure applied. For example, after wearing a tight seatbelt, or wearing a tight watch strap, or after gripping a tool such as a screwdriver for a reasonable period of time. The rash can be painful and tends to last several hours, or even a day or so.
Solar hives
This is a rare condition in which an urticarial rash develops on skin exposed to sunlight.
Water contact (aquagenic) hives
In this rare condition, an urticarial rash develops on skin exposed to water of any temperature.
Vibratory hives
In this rare condition, the rash comes up after using vibrating tools.
An itchy rash is the main symptom of hives (urticaria). The rash can appear anywhere on the body. Small raised areas called weals develop on the skin. The weals look like mild blisters and are itchy. Each weal is white or red and is usually surrounded by a small red area of skin which is called a flare.
The weals are commonly 1-2 cm across but can vary in size. There may be just a few but sometimes many develop over various parts of the body. Sometimes weals that are next to each other join together to form larger ones. The weals can be any shape but are often round.
As a weal fades, the surrounding flare remains for a while. This makes the affected area of skin look blotchy and red. The blotches then fade gradually and the skin returns to normal. Each weal usually lasts less than 24 hours. However, as some fade away, others may appear. It can then seem as if the rash is moving around the body. The rash may clear completely only to return a few hours or days later.
Most people with acute hives do not feel ill; however, the appearance of the rash and the itch can be troublesome.
In some cases a condition called angio-oedema develops at the same time as hives. In this condition some fluid also leaks into deeper tissues under the skin, which causes the tissues to swell. See the separate leaflet called Angio-oedema for more details:
The swelling of angio-oedema can occur anywhere in the body but most commonly affects the eyelids, lips and genitals.
Sometimes the tongue and throat are affected and become swollen. The swelling sometimes becomes bad enough to cause difficulty breathing.
Symptoms of angio-oedema tend to last longer than urticarial weals. It may take up to three days for the swollen areas to subside and go.
A variation called vasculitic hives occurs in a small number of cases. In this condition the weals last more than 24 hours, they are often painful, may become dark red and may leave a red mark on the skin when the weal goes. Technically, this type of rash is not urticaria.
Are any tests needed?
Usually no tests are needed. The rash is very typical and is easily recognised as hives by doctors. In many cases you will know what caused the rash from the events leading up to it. For example if you have just been put on a new medicine, or if your skin came into contact with a nettle, or if you were stung by a bee.
A symptom diary
A symptom diary may be helpful in working out if there is a specific trigger or cause. If your diary shows you only develop the rash on days when you eat a certain food, for example, it may be obvious what the cause is. A diary might also show if the rash relates to stress, exercise or sunlight. It may help rule out certain causes.
Skin-prick allergy tests
In some cases if it appears to be related to an allergy, tests such as skin-prick allergy tests may be helpful. Tiny quantities of substances which might cause an allergy are placed on your skin in a special order. If the skin reacts, you may be allergic to that substance.
Blood tests
In other cases, blood tests for allergy may be useful. In some people, blood tests may help to point to a cause. These may be general blood tests, or blood tests to look for specific proteins produced by your immune system, called autoantibodies. Where these are found, it is likely that it is your own immune system over-reacting which is causing the rash. Blood tests can be done by any GP, whereas skin-prick tests have to be requested by a consultant or member of their team, or a GP with a particular interest in allergy who works in a specialist clinic.
Exclusion tests
In some people, 'exclusion' or 'challenge' tests may be needed. For example, testing to see if cold or pressure always causes the rash, or excluding certain foods from the diet to see if that stops the rash from coming back.
Biopsy
Occasionally, if urticarial vasculitis is suspected, a sample of the skin may be taken (a skin biopsy) for further analysis.
Often no treatment is necessary, as the rash commonly goes within 24-48 hours. A cool bath or shower may ease the itch. Calamine lotion or menthol 1% in aqueous cream can help with itching, although if it is left on for too long the itch may come back. These can be bought without a prescription.
Once you know what causes the rash, it may be possible to avoid situations that trigger it. For example, dermatographism can often be prevented by avoiding firm pressure against the skin as much as possible. In mild cases, no additional treatment may be needed.
Various other factors may make symptoms worse (but are not the main trigger). The following are tips that some people have found helpful; however, there is little proof that they work in everybody:
Try avoiding tight clothes if weals occur at sites of local pressure. For example, under belts, under tight-fitting shoes, etc.
Try keeping cool, as hives may tend to flare up in warmer conditions. In particular, keep the bedroom cool at night.
For some people alcohol, hot baths, strong sunlight, and emotion make symptoms worse. If you think any of these are making symptoms worse then it may be helpful to try to avoid them.
See a doctor if you think a medicine is making symptoms worse, as a change in medication may be an option. Some medicines that may be triggers include aspirin, anti-inflammatory painkillers, and angiotensin-converting enzyme (ACE) inhibitors.
Antihistamines
Many types of hives are helped by taking antihistamine medicines. (However, these medicines may not help some cases of delayed pressure hives.) Antihistamines block the action of histamine which is involved in causing hives. The most commonly used antihistamines for hives are cetirizine, fexofenadine and loratadine. These do not usually cause drowsiness.
Your doctor may advise doses which are higher than the usual recommended dose in order to control the rash. If the itch is making it difficult to sleep, sometimes an antihistamine which makes you sleepy can also be taken at night. Examples of antihistamines used in this way include chlorphenamine or hydroxyzine.
Antihistamines can be bought over the counter, without a prescription. However, if you need to take them for more than a few days, or on a regular basis, it is best to see your doctor for further advice. Do not take more than the recommended dose without discussing it with your doctor. Antihistamines are not usually advised in pregnancy.
Some people take antihistamines now and then when a rash flares up. If you take an antihistamine as soon as the rash appears, the rash tends to fade more quickly than it would do normally. If the rash recurs frequently then your doctor may advise a regular dose of an antihistamine to prevent the rash from occurring.
If you have cholinergic urticaria and know that you get a rash on exercise, a dose of an antihistamine just before you do exercise may help to prevent or limit a flare-up of the rash.
Steroid tablets
Unlike most other types of hives, those caused by a physical stimulus are not usually helped by steroids. Occasionally for severe flare-ups of hives, a course of prednisolone tablets taken for a week may be helpful.
Other treatments
If you have a severe episode of hives then you may be referred to a specialist. Skin specialists (called dermatologists) or allergy specialists (called immunologists) may be able to help. In particular, if angio-oedema or anaphylaxis occurred at the same time, you would be referred or admitted to hospital. This is to reverse the reaction quickly. It is also to confirm the diagnosis and, where possible, to identify a cause. For example, if a nut allergy is suspected to have caused a severe episode then this can confirmed by tests. You may then be given advice on how to avoid the cause and on what to do if it should occur again.
Occasionally other treatments may be used, such as a tablet called montelukast, which is usually used for asthma. This may be particularly useful in delayed pressure urticaria, where antihistamines often do not help.
Omalizumab is a newer medication which acts against autoantibodies produced by the body's own immune system. It has to be given by injection once a month. This has been shown to be effective for some types of inducible urticaria in some studies. In the UK the National Institute for Health and Care Excellence (NICE) has recommended its use for chronic spontaneous urticaria where other treatments have not worked. It has to be given by a hospital consultant.
Treatment with ultraviolet light (phototherapy) can cause an improvement in symptoms but, unfortunately, this may only last for a few months.
Usually not. The rash is itchy but normally fades within a day or so and causes no harm. Most people with hives (acute urticaria) do not feel too unwell unless they have a cold or flu that is triggering the rash. The cause of the rash is not known in more than half of cases and it is commonly a one-off event.
However, hives may be more serious in the following situations:
Food allergy. If a food allergy is the cause then the rash is likely to return each time you eat the particular food. This is more often a nuisance than serious.
Severe allergies. People who have a severe allergic reaction to peanuts, insect stings, etc, often have an urticarial rash as one of the symptoms. This is in addition to other symptoms such as severe angio-oedema, breathing difficulties, collapse, etc. A severe allergic reaction is called anaphylaxis. Note: most people with acute urticaria feel well and do not have anaphylaxis.
No. Whilst other causes of a skin rash are contagious, hives aren't
Inducible urticaria most commonly occurs in healthy young adults. You can have two or more different types of hives at the same time. As a rule, hives triggered by physical stimuli tend to improve and become less troublesome with time (often going, or being much less troublesome, after 2-5 years).
Acute hives usually last less than six weeks. Most cases last 24-48 hours and in some cases the rash only lasts a few hours.
Persistent hives tend to come and go. You may have times when the rash appears on most days, and then times when the rash may go away for a while. The severity of the rash and itch varies from person to person. Some things such as heat, cold, menstrual periods, stress, or emotion may make the rash flare up worse than usual.
Symptoms may go away completely after a few months; however, the condition lasts several years in some cases.
In about half of cases, symptoms go within 3-5 years after the condition first starts.
In about 1 in 5 cases the symptoms persist on and off for more than 10 years.
There are usually no serious complications, but the itch can be very annoying and difficult to ignore. If skin is scratched excessively then there is a risk of infection.
