Hives

and Martina Feichter, medical editor and biologist

Hanna Rutkowski is a freelance writer for the medical team.

More about the experts

Martina Feichter studied biology with an elective subject pharmacy in Innsbruck and also immersed herself in the world of medicinal plants. From there it was not far to other medical topics that still captivate her to this day. She trained as a journalist at the Axel Springer Academy in Hamburg and has been working for since 2007 - first as an editor and since 2012 as a freelance writer.

More about the experts All content is checked by medical journalists.

Hives (medical urticaria) is one of the most common skin diseases. Typical symptoms are reddened skin and very itchy wheals. Sometimes the skin and mucous membranes also swell. The hives can occur acutely or chronically and have various triggers. Read more about the causes, symptoms, diagnosis, treatment and prognosis of hives here!

ICD codes for this disease: ICD codes are internationally recognized codes for medical diagnoses. They can be found, for example, in doctor's letters or on certificates of incapacity for work. L50

Hives: quick reference

Symptoms: reddening of the skin, very itchy wheals and / or swelling of the skin / mucous membranes (angioedema)
Causes: very diverse. Sometimes there is an allergy behind it, but often the hives are not allergic either. Possible triggers are, for example, intolerance to food or medication, physical stimuli (cold, light, pressure, etc.), autoimmune reactions or chronic infections.
Forms of urticaria: spontaneous acute hives, spontaneous chronic hives, physical forms of hives, aquagenic hives, exercise-induced hives, etc.
Treatment: Avoid the trigger or treat the cause. Medicines (antihistamines, cortisone, etc.). In certain cases further therapy such as UV treatment.

Hives: causes and risk factors

The development of hives is very complex. We know that the typical itchy rash forms when certain immune cells (mast cells) release inflammatory messenger substances in response to irritation. The tissue hormone histamine is one of these messenger substances: It is mainly responsible for the symptoms of hives (wheals, itching, reddening of the skin, swelling).

The fact that the mast cells release more inflammatory messengers can be an allergic reaction (to food, pollen, etc.). However, the mast cells can also be activated in other ways. That means: not every hives is caused by allergies.

This is what happens with hives

Certain allergens or other irritants lead to the release of inflammatory messenger substances (especially histamine). The typical symptoms of hives arise.

When looking at the noticeable skin symptoms, many people fear that hives are contagious. But the concern is unfounded: There is no risk of infection from the patient!

Different forms of hives

There are several subtypes of hives. They don't always appear individually: some patients have two or more of these subtypes at the same time.

"Keep a diary"

Three questions for

Dr. med. Elisabeth Schuhmacher,
Specialist in dermatology
1
Is Hives Contagious?

Dr. med. Elisabeth Schuhmacher
Many are shocked when they see the skin changes. But fear not, hives are not contagious. Be sure to see a doctor. The best thing to do is to see a dermatologist who is also an allergist. In preparation, you should keep a diary. Enter when the symptoms occur and what you have eaten and drunk when and what medication you have taken and when - as precisely as possible.
2
Once I have spontaneous hives, do I tend to?

Dr. med. Elisabeth Schuhmacher
That depends a bit on the cause - and whether you can clearly identify it, but in principle you can answer with "yes". Sometimes, for example, certain drugs cause the skin reaction. The triggers should then be avoided in the future.
3
Are there home remedies that can help relieve symptoms?

Dr. med. Elisabeth Schuhmacher
It is important that you see a doctor to rule out complications. Sometimes the larynx tissue swells, which can cause shortness of breath. To do this, the doctor equips you with an emergency kit. Otherwise, antihistamines and lotions will help against the itching. It is good if you pay attention to your intestinal flora and strengthen them in a targeted manner. Also have a possible histamine intolerance or allergies clarified. And: Take care of yourself and lead a good life.
Dr. med. Elisabeth Schuhmacher,
Specialist in dermatology
Dr. med. Elisabeth Schuhmachers runs her own private practice for dermatology and aesthetic medicine in Munich.

The different forms of disease can be divided into three large groups:

Spontaneous hives: Here wheals and / or angioedema suddenly develop without the doctor and patient being able to recognize an external trigger. This urticaria appears "out of nowhere". Depending on how long the symptoms last, a distinction is made between spontaneous acute and spontaneous chronic hives (see below). About 80 percent of all patients have spontaneous urticaria, two thirds of them an acute variant.
Physical hives: This includes all forms of hives that are triggered by physical stimuli (such as pressure, wind, cold contact, etc.). They only make up about 10 percent of all hives.
Other forms of hives: The causes here are, for example, physical exertion, contact with water or sweating. Such special forms of hives are found in less than 10 percent of all patients.

The different forms of urticaria are described in more detail below.

Spontaneous acute hives

The hives symptoms appear suddenly without any recognizable external stimuli, but last for less than six weeks.

A specific hives trigger can rarely be found. A striking number of those affected suffer from acute infections of the respiratory tract or the digestive tract; a connection therefore seems likely. An intolerance or allergy to certain foods or food additives (dyes, preservatives, etc.) are also possible causes.

The same applies to certain drugs, for example. These include so-called non-steroidal pain relievers such as acetylsalicylic acid (ASA) and ACE inhibitors (for high blood pressure and heart failure). They often cause pseudo-allergic reactions in the skin.

An acute hives becomes threatening when the mucous membrane of the respiratory tract (throat, larynx, etc.) swells considerably (angioedema). Then the air you breathe can only get through with difficulty or not at all. Those affected get breathlessness and can even suffocate!

In the event of sudden shortness of breath, you should always alert the emergency services immediately (No. 112)!

Spontaneous chronic hives

If a spontaneous urticaria persists for more than six weeks, it is called "spontaneous chronic urticaria" (or simply "chronic urticaria"). The hives symptoms can either persist (continuously) or occur repeatedly (with more or less long symptom-free phases in between).

Many triggers of spontaneous acute hives can also be responsible for spontaneous chronic hives. In some patients, several different factors also trigger chronic urticaria.

The main causes of spontaneous chronic hives are:

Chronic infections: Chronic or frequently recurring infections such as sinusitis, tonsillitis or jaw abscesses can trigger chronic urticaria. Many patients are also infected with the stomach germ Helicobacter pylori infected. The chronic infections do not necessarily have to trigger other symptoms besides urticaria.

Autoimmune reactions: In some patients, immune cells act against the body's own cells (autoantibodies), e.g. against mast cells. This can also trigger spontaneous chronic hives. It is also called "autoreactive hives".
Hypersensitivity (pseudoallergy): Here the immune system is hypersensitive to certain additives in food (dyes, preservatives, etc.), to natural flavorings in fruit or vegetables, or to cosmetics or medicines.

Sometimes chronic urticaria also develops for other reasons, such as an allergy.

Physical hives

An itchy nettle rash can also be triggered by a variety of physical stimuli (pressure, cold liquid, etc.): In the event of direct skin contact, an itchy rash forms at the point of irritation. However, it can also occur in another area of the body and also provoke low blood pressure or a fast heartbeat.

Depending on the physical stimulus, a distinction is made between different types of hives:

Urticaria factitia (urticarial dermographism): It is triggered by shear forces acting on the skin. Such shear forces arise, for example, when scratching, rubbing and rubbing the skin.
Delayed pressure urticaria: Persistent pressure triggers the nettle rash at different times - the wheals do not form until three to twelve hours later. Therefore, those affected often do not recognize the direct connection with the impact of pressure.
Cold contact urticaria: The trigger is contact with cold objects, cold air, cold wind or cold liquids. For example, itchy rashes or redness can form on uncovered parts of the body in winter.
Heat contact urticaria: The trigger here is localized contact with heat (blow-drying, hot foot bath, etc.).
Light urticaria: Both UV light (e.g. in the solarium) and visible light can be the cause.
Vibratory urticaria: Vibrations such as those caused when working with a jackhammer are also possible triggers for hives.

Familial cold urticaria is a rare, genetic disease that is not part of the classic hives (despite the similar name)!

Special forms of hives

Cholinergic urticaria is caused by an increase in the core body temperature. This can happen, for example, when you eat spicy food or take a hot bath. Physical exertion and emotional stress can also raise the temperature inside the body. As a result, pinhead-sized wheals form, but they disappear again within an hour. General symptoms are also possible (dizziness, nausea, headache, etc.). This form of hives mainly affects adolescents and young adults.

Exercise can also trigger what is known as exercise-induced urticaria. Compared to cholinergic urticaria, the wheals are larger than the head of a pin and the general symptoms (including shock) are more frequent. Sometimes the symptoms appear after a meal, within four to six hours. These symptoms are then both exercise and food-induced.

In contact urticaria, the nettle rash results from contact with so-called urticariogenic substances. Sometimes these are substances that the person is allergic to, such as certain foods or latex.

Contact urticaria can also occur independently of an allergy when irritants are touched. These can be, for example, the fragrance Peru balsam (in cosmetics, medicines, cleaning agents, etc.), the preservative benzoic acid (food, etc.) or certain plants. A well-known example are the itchy wheals caused by skin contact with nettles (this plant is also the namesake of hives).

Very rarely, urticaria develops through contact with water - regardless of the temperature. This so-called aquagenic urticaria can put a lot of strain on those affected: the skin can react with itchy wheals when showering, swimming or a heavy shower of rain. But this is not an allergy to the water!

Hives: treatment

The hives therapy is made up of different components. The attending physician will adapt them individually to each patient. The type of urticaria and the severity of the symptoms play a role in this.

Avoid triggers

The most important building block of hives therapy is to avoid the trigger as much as possible. Of course, this is only possible if it can be clearly identified.

If it is about certain foods, those affected should avoid them. If certain drugs are the trigger, they should be discontinued if possible. If that is not possible, they can often be exchanged for a better tolerated active ingredient.

Pressure urticaria can be prevented by only shouldering backpacks and bags with wide straps. If chronic infections (stomach germs, infections of the upper respiratory tract, etc.) turn out to be the cause of chronic hives, they must be treated properly.

It can become more difficult if, for example, physical stimuli such as heat or friction cause the hives. The stimulus threshold is often very low here. For example, people with urticaria factitia sometimes develop hives while wearing clothes that are not completely loose. In addition, some physical stimuli (cold wind, UV rays, etc.) can hardly be completely avoided.

Medicines for hives

Various groups of drugs are available for treating hives:

Antihistamines

The antihistamines are among the most important drugs in the treatment of hives. They can be effective in alleviating the allergic and allergy-like symptoms in many patients. This is because antihistamines inhibit the effects of histamine. This messenger substance is mainly responsible for the symptoms of hives.

As a rule, so-called H1 antihistamines of newer generations are used, which do not have a sedative effect on the brain, i.e. do not make you tired and sleepy. Examples of such active ingredients are loratadine or desloratadine and cetirizine.

Antihistamines are usually taken as tablets. If the acute symptoms of hives are severe, it may be necessary to give the drug as an infusion.

So-called H2 antihistamines can also inhibit the effect of the histamine (in a different way than H1 antihistamines). However, they are only used in the treatment of hives in special cases, such as chronic urticaria that is difficult to treat.

Glucocorticoids("Cortisone")

In severe cases, urticaria must often be treated with cortisone (such as prednisolone). This can be the case, for example, when antihistamines do not sufficiently help against the symptoms of hives.

The active ingredient is administered either in tablet form or as an infusion (in acute cases). Sometimes the doctor will also prescribe an ointment containing cortisone, for example for pressure urticaria.

In general, cortisone should only be used for a short time and in low doses, if possible. This lowers the risk of side effects.

Leukotriene antagonists

These drugs have anti-inflammatory and anti-allergic effects. The active ingredient montelukast in particular is sometimes used in hives that are difficult to treat. For example, if you can't get chronic hives under control with antihistamines, the doctor can also prescribe montelukast. This active ingredient is also an option for some other forms of urticaria (such as cold urticaria) if other treatments are not effective enough.

Immunosuppressants

These are drugs that suppress the immune system. They are very effective but are not considered the standard treatment for hives either. In some patients with chronic urticaria, the symptoms can only be relieved with an antihistamine plus an immunosuppressant (such as ciclosporin A). The doctor will closely monitor the treatment in order to identify any side effects early on.

More medication

Treating hives can be difficult, especially those with chronic or chronically recurring symptoms. In severe cases, it may then be necessary to administer other active ingredients to a patient - in addition to or as an alternative to the above-mentioned drugs. Some examples:

For spontaneous chronic urticaria, doctors sometimes prescribe the active ingredient hydroxychloroquine when other treatments do not help. This anti-inflammatory and anti-parasitic drug is mainly used for other diseases such as malaria and lupus erythematosus.

Some patients with chronic hives that are difficult to treat also benefit from treatment with omalizumab. This is a special antibody that blocks the release of inflammatory messenger substances from the mast cells.

For persistent cold urticaria, some patients are given antibiotics (such as penicillin) on a trial basis.

Hives: other treatments

In addition to medication, other treatments are sometimes considered for severe hives, depending on the form of the disease.

This includes, for example, habituation therapy ("hardening"): It is useful if antihistamines do not help with light urticaria, for example. Then the skin can be exposed to solar radiation repeatedly and in a targeted manner. This should cause the body to slowly develop a tolerance to light. Stubborn cold contact urticaria can sometimes be treated in the same way (for example, by taking regular cold showers). A habituation therapy must be carefully considered and accompanied by a doctor. This is because it can put a considerable strain on the patient.

In the case of urticaria factitia that is difficult to treat, targeted irradiation with UV-B light (UV-B therapy) can be useful.

Hives & Home Remedies

Home remedies can help with acute urticaria attacks and support the effects of medication:

Cold against itching: The itching can be relieved with cool compresses or a cold shower - but only if it is not a cold urticaria!
Baking soda: It calms the annoying itch if you stir it with a little water and apply it to the skin as a paste. You can also use it as an additive in bath water.
Medicinal plants: Hamamelis (witch hazel) has an anti-inflammatory effect, soothes itching and constricts the blood vessels. This is why ointments or creams with witch hazel are ideally suited to alleviate all symptoms of hives. The marigold also has similar effects.
Vinegar wrap: A tried and tested remedy for itching is the vinegar wrap. Moisten a kitchen towel with a mixture of vinegar and water and place it on the skin.

Hives & Homeopathy

Some swear by the effects of homeopathy in the lengthy treatment of chronic urticaria.However, in order to find the right remedy, the cause must also be known here. An experienced homeopath can choose the right homeopathic remedy for each patient. For example, they are used Urtica urens (Stinging nettle), Acidum formicicum (Formic acid) and Sulfur (Purified sulfur). The conventional medical treatment of hives is usually supplemented with homeopathy.

Hives: symptoms

Even if the triggers are very diverse - the hives causes symptoms with a typical appearance:

reddened skin
very itchy skin blisters (wheals)
sometimes extensive swelling of the skin / mucous membranes (angioedema)

One of the messenger substances that are increasingly released in hives: histamine is primarily responsible for these symptoms. It dilates the small blood vessels in the skin, causing the skin to turn red. At the same time, the vessels become more permeable. As a result, more fluid passes into the tissue: wheals are formed. These are superficial elevations of the skin of variable sizes, which are almost always surrounded by reddening. They are fleeting: they go away on their own within 24 hours. At the same time, however, new wheals can form elsewhere.

Sometimes the wheals are confined to a limited area, in other cases they practically cover the whole body. They are accompanied by severe itching. It can be relieved somewhat by rubbing and rubbing the affected areas of the skin, but less by scratching. That is why the skin is rarely scratched, even when it is extremely itchy.

In some patients with hives, there is sudden, pronounced swelling of the skin / mucous membrane, for example on the face. These so-called angioedema can be accompanied by an uncomfortable feeling of tightness and itching. They resolve more slowly than wheals (within 72 hours). Swelling of the mucous membranes in the airways (throat, larynx, etc.) can be dangerous (shortness of breath!).

Some patients only have the wheals, others (rarely) only the angioedema. Still others have both developed hives symptoms.

Hives: examinations and diagnosis

The reddish, itchy wheals are a typical clinical picture that quickly suggests the diagnosis of hives. It is often more difficult for the doctor to find out the exact cause of the urticaria. The simplest, but most important means for this purpose is a thorough patient survey: During the conversation, the doctor collects the patient's medical history (anamnesis). To do this, he has the symptoms described in detail, asks about any previous or underlying diseases and possible triggers of the hives. Frequent questions from the doctor are:

What are your symptoms and how long have they existed?
Is there a connection between the symptoms and your job, your hobbies, possible travel or leisure activities, the menstrual cycle?
Are there any cases of hives or atopic diseases (neurodermatitis, hay fever, allergic asthma, etc.) in the family?
Did you have or do you have an allergy or intolerance (to food, medication, etc.)?
Are you known to have any infections, psychosomatic or psychiatric illnesses?
Do you have any suspicions as to what could trigger the symptoms (certain foods, alcohol, smoking, cosmetic products, cold, physical exertion, stress, etc.)?
What medications do you use (occasionally or more often)?

Tip: If hives are persistent or recurring, patients should keep a diary in which they document the extent of their symptoms. At the same time, they should write down what they ate and drank and what medication they used. Other possible influencing factors on the disease should also be noted. This can help the patient and doctor to find the cause of the hives.

In the case of spontaneous acute hives, often no further diagnostic steps are necessary. However, if the urticaria is suspected to be an allergic reaction, the doctor can perform allergy tests (such as prick tests) to find the trigger.

Further investigations in certain cases

Spontaneous chronic hives and other forms of urticaria require further investigation:

In the case of chronic hives, laboratory tests can help uncover possible infections or other diseases as a trigger. For example, a blood sample is used to determine the differential blood count and inflammation parameters (such as CRP). If the patient may have a chronic infection or inflammation in the upper respiratory tract or teeth, a visit to the ENT doctor or dentist may be useful.

The patient's blood can also be tested for antibodies against infectious agents, for example against the bacterium Helicobacter pylori. If antibodies against this stomach germ are actually found, a stool sample and a mucous membrane sample from the stomach can confirm the infection.

The detection of so-called autoantibodies in the blood - i.e. antibodies that act against the body's own tissue - is also revealing. You could be the trigger for the chronic hives. Such an autoreactive hives can be clearly demonstrated with a simple test (ASST = Autologous serum skin test).

Sometimes chronic hives arises from the fact that the patient does not tolerate certain ingredients of food (no allergy!): The hives are then a pseudo-allergic reaction to this irritant. For clarification, the doctor can recommend a special diet for three weeks: During this time, the patient should avoid all foods that contain flavorings, preservatives, colorings or antioxidants. The ban primarily affects industrially processed foods. If this low-pseudo-allergen diet relieves the symptoms, such additives are likely to be the trigger for the hives.

A targeted provocation test can be carried out to confirm this: For a while, suspicious foods are consumed in large quantities. Such provocation tests can also be used to identify physical stimuli as triggers for hives. A part of the body is exposed to a certain stimulus. This can be cold or hot water, light or pressure.

The doctor may rub the skin with a blunt tip. If this then turns red, forms wheals and starts to itch, urticarial dermographism (urticaria factitia) is present. The suspicion of aquagenic urticaria can also be clarified with a provocation: A wet compress at body temperature is placed on the skin for 20 minutes.

Allergies are rarely the cause of chronic hives. However, if there is a corresponding suspicion, allergy tests bring clarity.

If the doctor suspects that the chronic rash is caused by a so-called mastocytosis, he takes a small sample of skin in the area of the wheals and has it examined in the laboratory. The term mastocytosis refers to diseases caused by an excessive number of mast cells in the body. If this excess is limited to the skin, it is known as cutaneous mastocytosis. It is also called urticaria pigmentosa. It used to be considered a sub-form of "conventional" hives, but is no longer the case.

For hives in children, experts recommend the same diagnostic steps as in adults. The possible causes of urticaria are the same in both age groups. There are only differences in the frequency of the various subtypes of hives.

Hives: course and prognosis

Around one in five Germans (20 percent of the total population) will develop urticaria in the course of their life. Usually it is an acute hives. It usually disappears within a short time.

In a small proportion of those affected, the wheals and itching persist for more than six weeks. Then a chronic hives developed. Often the trigger can be identified. Then you can usually treat it (infections or other diseases) or largely avoid it (medication, additives in food, etc.).

If the cause of chronic urticaria cannot be determined, the symptoms can at least be alleviated (with medication, etc.). There is a little consolation for the patient: at some point every chronic hives will heal on its own. However, this can take years or even decades.