Breaking out in beehives for no apparent reason
Sometimes the source of the raised, red, itchy bumps on your skin can be a mystery.
One of the reasons that hives can be so surprising is that it can be caused by many things you don’t expect, including stress and exercise. Most of these unexpected causes of hives aren’t serious, but some indicate it’s a good idea to make an appointment with a doctor.
Read on for more information on why you may have hives.
Urticaria is an itchy reaction on your skin. They happen when a chemical called histamine is released in your body.
They can appear anywhere on your body and can be tiny bumps the size of a pin prick or large raised areas that cover an entire limb. Hives often appear red or pink on white or fair skin. People with darker skin may have hives that are slightly lighter or slightly darker than the skin around them.
Regardless of the color of your hives, all hives share these qualities:
- round, oval or irregular shape
- clearly defined border
Urticaria is also called hives. Sometimes the cause of hives is obvious. For example, you might have an immediate reaction to something you’re allergic to, like pollen or pet dander. However, the cause is not always clear. Hives can be sudden and surprising and don’t seem to have a cause.
Urticaria is a very common skin reaction that can come from unexpected sources. Some causes that you may not have thought of include:
- Colds and other viral infections. Sometimes hives can be caused by your immune system fighting off colds and other viral infections. These hives often appear towards the end of your cold or virus when you start to feel better. They are more common in children, but can happen to anyone.
- Bacterial infections. Bacterial infections such as strep throat or urinary tract infections can also sometimes trigger hives when your body reacts to the bacteria. These hives will subside as the antibiotics help your body fight off the infection. They might peel before they heal completely.
- Chronic diseases such as lupus. Hives that lasts longer than 6 weeks may be a sign of an autoimmune disease such as lupus, type 1 diabetes, thyroid disease, or rheumatoid arthritis. These hives will not go away on their own. It is a good idea to make a medical appointment to have this type of hive examined and see if chronic disease is the cause.
- Stress. Stress can raise your internal body temperature and release adrenaline and other chemicals that could trigger hives. Stress hives tend to be found on the face, neck, chest, and arms. They are common in people with eczema, allergies or sensitive skin.
- Temperature changes. A sudden encounter of heat or cold, such as stepping into a wet shower or entering a swimming pool, can cause the release of histamine and the formation of hives. Hives that form in response to temperature are called cold urticaria. A red, itchy area of skin often forms around these hives.
- Tight clothes. Tight clothing can cause friction which can lead to irritation and hives. Clothing that sits close to your skin can also push bacteria on the surface of your skin into your pores and hair follicles.
- Exercise. A chemical called acetylcholine that is released in your body when you exercise can affect your skin cells and cause irritation and hives. Exercise hives are known as exercise-induced hives. Some people have additional symptoms in addition to hives, such as shortness of breath, headache, flushing, and stomach cramps.
- Inflammation of the blood vessels. An inflammation of your blood vessels known as vasculitis can cause painful hives. They can leave a bruise on your skin and last for several days. Vasculitis is a serious medical condition that requires treatment by a healthcare professional.
- Medications. Certain medications, including nonsteroidal anti-inflammatory drugs (NSAIDs), antibiotics, and opioids, can cause an allergic reaction that leads to hives. Hives after drug treatment can be the first sign of a medical emergency called anaphylaxis. Other symptoms of anaphylaxis include shortness of breath, wheezing, vomiting, and loss of consciousness.
Urticaria is often caused by identifiable allergies. Avoiding these allergens can help you avoid rashes. Common beehive triggers include:
Hives can be a sign of a serious allergic reaction that needs urgent medical attention. It is important to take action if you have hives with any of these symptoms:
- tightness in the chest or throat
- difficulty in breathing
- difficulty speaking
- swelling of the throat, face, or tongue
If you have any of these symptoms, call 911.
A doctor may prescribe an epinephrine injector, such as an EpiPen, for future allergic reactions. They will teach you how to use it and answer all your questions. You will keep your epinephrine injector handy and use it if you develop hives in the future.
You will still need to go to the emergency room after using your epinephrine injector, but this can prevent anaphylaxis from becoming fatal.
A doctor can diagnose hives and help you find the cause. They might recommend that you keep a food diary to find out if there is a connection between the food and your hives.
You may be referred to an allergist, a doctor who specializes in treating allergies, for further testing. This can include blood work and urine tests to look for chemicals in your body that could tell allergists what is causing your hives.
You may also have a skin biopsy, especially if your allergist suspects vasculitis is causing your hives. Hives that have lasted longer than 6 weeks will likely require testing for underlying chronic conditions.
Sometimes a specific cause is not found. In this case, your hives will be diagnosed as idiopathic hives. The word “idiopathic” means unknown. In this case, your doctor will still be able to help you with a treatment plan, but you will not be able to tell what to avoid to prevent hives in the future.
Treatment for hives will depend on the severity of your hives and the cause. For example, you will need to avoid the cause of your hives if it has been found.
Your doctor will work with you to find the treatment that’s right for you. Common options include:
- Antihistamines. Over-the-counter and prescription antihistamines block histamine and can treat hives. You may find that some antihistamines work better for you than others. Sometimes a combination of antihistamines is recommended.
- Anti-itching lotions. Itching and redness lotions can relieve hives and prevent scratching.
- Antibiotics. Hives linked to bacterial infections can be treated with antibiotics
- Corticosteroids. Corticosteroids may be taken short-term to help with severe cases of hives.
Learn more about hives treatment options.
Hives can sometimes be surprising and have no obvious cause. There are actually a wide variety of things that can cause hives, including stress, colds, exercise, and temperature changes. Chronic urticaria can indicate an underlying condition such as lupus.
An allergist can help you determine the cause of your hives and start treatment.