What is Urticaria?
Urticaria is an outbreak of pale red bumps and welts on the skin. Sometimes these welts can join together to form large areas called plaques.
These hives can be caused by a variety of things, including allergies and sunlight. They can also be a sign of a serious allergic reaction known as anaphylaxis.
Causes
Urticaria is a skin condition that causes itchy, raised, red rashes. It can appear in one spot or spread across large areas of the body.
Urticaria – which is also known as hives – usually clears up within a few minutes to a few days and can be treated by taking a non-drowsy antihistamine. However, if the rash occurs most days for more than six weeks this is considered chronic urticaria.
Acute urticaria develops when a trigger – such as an allergic reaction, a cold or sunburn or exposure to a particular medication – causes high levels of histamine and other chemical messengers to be released in the skin. These chemicals cause blood vessels in the affected area to open up and become leaky, leading to swelling and itching.
The rash can last for up to 48 hours, and the symptoms are itchy and stinging. This is not a life-threatening condition, but it can be very uncomfortable and can stop you from enjoying your normal activities.
In most cases, urticaria is caused by an allergy or an irritant, such as latex or an insect bite. If you have urticaria, your GP may be able to identify the trigger by asking you questions or performing allergy tests.
Some people can’t find the cause of their urticaria, and it can last months or years. These are called chronic hives and are harder to diagnose than acute urticaria.
It’s usually caused by rubbing or scratching, but can occur after exposure to hot and cold temperatures (cholinergic urticaria) or a change in the temperature of the skin (solar urticaria). It tends to affect people who spend a lot of time outdoors and often improves after a short break from these activities.
Delayed pressure urticaria can appear six to eight hours after pressure has been applied, such as when wearing a belt or a constrictive pair of clothing. It can also be associated with a fever, joint pain and swelling.
In rare cases, urticarial vasculitis can develop, causing the blood vessels in the skin to become inflamed and the weals or raised areas last longer than 24 hours and are more painful. Treatment can include steroids, leukotriene receptor antagonists, prednisolone and immunosuppressives.
Symptoms
What is Urticaria and how to treat it?
Urticaria is a condition that causes itchy rashes, which can vary in appearance and size. The rash is commonly red or pink, sometimes with a stinging sensation and can itch intensely. The rash can appear in one area or spread over the skin, and can last for a few days to a few months.
About a quarter of people have hives at some time in their lives. They often develop when immune cells in the skin called mast cells are activated by a reaction. Mast cells release natural chemicals, including histamine. These chemicals cause the itching, redness, and swelling of the skin in an area known as a hive.
Acute urticaria is a short-term rash that typically lasts six weeks or less. The rash can be caused by a number of different things, including allergies, medications, insect bites, stings, blood transfusions and infections.
Most cases of acute urticaria get better on their own without medical treatment. However, some people have chronic urticaria which can be a problem for life. This type of urticaria isn’t clear what causes it, but can be very uncomfortable and interfere with daily living.
The symptoms of urticaria are usually itchy and red in colour, but some can be more painful or leave a bruise. The rash can look like little red or pink bumps or lumps on the skin, but they may not be visible at all.
Some types of urticaria are caused by allergic reactions, so allergy tests are often done when symptoms occur. These tests can be used to identify the exact cause of the rash.
If the urticaria is caused by an allergy, you will need to take allergy medications to relieve the itching. These can be available over the counter in pharmacies and may help reduce the itchiness and discomfort.
You will also be asked to avoid any irritants that could trigger an allergy. Taking these steps can prevent the hives from appearing again.
Other treatments can be prescribed if the hives are caused by an illness or condition, or if they don’t improve on antihistamines. They can include omalizumab, which is injected under the skin once a month and can be very effective in some cases of chronic urticaria. Corticosteroids may be used for severe itchy hives.
Diagnosis
Urticaria is a condition that causes itchy, swollen and red patches on the skin. It may occur in children and adults, and it can last for a long time.
It is often treated by your GP. They will take a good look at the rash and ask questions to find out what is causing it. They may refer you to a specialist who can carry out allergy tests. They may also do blood tests, including a full blood count (FBC).
You can have a number of different types of hives. They are classified as acute or chronic based on how long they last. Acute hives usually get better within a few days. If they keep coming back, you might have a food allergy. You should keep a diary to help your doctor identify the cause.
If you have urticaria that lasts for more than six weeks, you should see an allergist/immunologist. They will take a detailed medical history and ask about your and your family’s eating habits. They will also ask about your medication, if any.
A chronic case of urticaria may be caused by an autoimmune response, which means the immune system is mistakenly attacking healthy cells in your body. This can happen when you have an underlying autoimmune disease such as diabetes or arthritis, or it could be due to something else entirely.
Your GP will ask you about the symptoms, when they started, where the hives are and how they feel. They will also ask about your family’s medical history, what you eat and any medications you take.
They will also ask about any recent changes in your life. It might be that you have moved, or you are going on a holiday.
You will need to explain what you eat, your stress levels and anything that makes your hives feel worse. You can be given a few antihistamines to treat your urticaria. They are available at most pharmacies.
You might need to take corticosteroids or steroid tablets if your urticaria is severe. They can be given in small doses to ease the itching and swelling, but they should not be used over a long period.
Treatment
Urticaria is a condition that causes itchy, raised skin patches (weals). Around one in five people will experience urticaria at some point in their lives.
It can be very upsetting and is a cause of stress for many people. However, effective treatments are available. It is important to see your GP if your urticaria is getting you down.
Treatment aims to relieve itching and reduce the swelling of the affected skin, called erythema. Antihistamines and short courses of oral corticosteroids (tablets) can help.
Identifying the causes of urticaria is key to treating it effectively. Symptoms may be triggered by a particular allergen or irritant, or they could be due to a condition such as an autoimmune disease.
Allergen-mediated urticaria occurs when a person reacts to an allergy trigger, such as a pollen or insect sting. A person with this type of urticaria will often have symptoms within minutes to a few hours after exposure to the allergen.
Most cases of urticaria are caused by a type of allergy known as an IgE-mediated reaction. This means that the body reacts to a certain protein that is contained in foods and in some insect stings, such as bee stings or wasp stings.
These reactions are usually very severe and last for a short time. The skin can swell up and become red or pink, itchy, and watery.
A number of different drugs can be used to treat the symptoms of urticaria, including antihistamines such as cetirizine and loratidine. Higher doses can be used if needed.
In addition to the use of drugs, there are a number of strategies that can be used to improve the symptoms of urticaria. For example, adding an H2 receptor blocker to a drug that normally binds to only H1 receptors can have a beneficial effect in patients who are not well controlled with antihistamines alone.
Another strategy is to reduce the amount of a particular food that causes the symptoms. This is known as reducing dietary pseudoallergens and should be tried for a trial period of at least three weeks.
