Hives: Causes, Symptoms, & Treatments

What Are Hives?

Hives are a type of skin rash typically triggered by allergies or an external stimulus like heat or rapid temperature changes. Also known by doctors as urticaria, hives are red, raised, and itchy welts that can come in a variety of shapes and sizes, from as small as a few millimeters to several centimeters or inches in diameter.

Hives can occur anywhere on the body, and they can quickly change in size and location. For example, someone could have hives on their arms and legs that disappear and then reappear on the abdomen and back, all in a matter of hours. Usually, the welts fade when a person’s allergic reaction is over. Hives are not contagious because they’re related to a person’s immune system, and they generally aren’t associated with any major, life-threatening complications.

Types of Hives

Acute hives

Acute hives occur when the rash appears abruptly due to an allergic reaction. This is a short-term response by your body to an allergen, and usually resolves within a few days of exposure to the trigger.

Chronic hives

It’s normal for hives to disappear once a person’s allergic reaction runs it course. However, some people experience chronic hives. Hives are considered chronic when welts appear on the skin for more than six weeks or recur spontaneously over the course of several months or years.

Doctors don’t fully understand what causes people to experience chronic hives. Some researchers suspect chronic hives are linked to a derangement of the immune system. Viruses like influenza or hepatitis B can cause chronic hives, and it’s thought that autoimmune disorders like lupus can as well.

What Causes Hives?

Most commonly, hives occur as a result of an allergic reaction. During an allergic reaction, a person’s body releases histamine in response to an allergen, causing capillaries to leak fluid into the bloodstream, causing swelling. Hives form as a result of this swelling and inflammation.

People’s allergic triggers differ. Some of the most typical hive-causing allergic triggers are:

• Foods like nuts, shellfish, and eggs
• Pet dander from animals
• Insect bites and stings
• High temperatures or a rapid change in temperature
• Exercise, especially in the heat
• Certain plants such as poison ivy, poison oak, or nettles
• Some medications, including antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), and ACE inhibitors, which are used to treat high blood pressure
• Viral infections, like the flu, the common cold, or mononucleosis (mono)
• Bacterial infections, like strep throat or urinary tract infections
• Chronic illnesses like lupus or thyroid diseases
• Cockroaches or cockroach waste

Sometimes, emotional stress can trigger hives, known as “stress hives.” This may happen because stress intensifies the body’s inflammatory responses.

Symptoms of Hives

Symptoms of hives can vary from person to person, but typically they include:

• Patches of round or oval-shaped, skin-colored welts or pink or red welts, which may turn white when you press the center (called “blanching”)
• Welts that change rapidly over time during the course of an allergic reaction
• Itching, which can be severe
• Swelling of the lips, eyelids, and extremities

While these symptoms can be uncomfortable and even painful, hives generally resolve on their own as the allergic reaction runs its course and the stimulating trigger is eliminated.

How Are Hives Diagnosed?

If you have hives and seek medical care, your doctor will perform a throughout history and physical exam to confirm the diagnosis and try to elicit the cause. If the cause of your hives is not easily identified, your doctor might ask you to keep track of:

• Your daily activities
• Medications and supplements you take
• What you eat and drink
• The symptoms you experience with your hives (like whether they swell)
• Where your hives appear on your body and how long they take to fade

In some cases your doctor may need more information about your potential allergies and you might undergo a skin test or blood test for further work up.

Treatment Options for Hives

The acute treatment for hives is focused on reducing the symptoms, while the treatment for chronic hives ultimately depends on the cause. Talk to your physician or a K doctor to learn more about treatments and identifying potential causes.

To manage allergy-induced hives and the uncomfortable symptoms that come with them, your doctor may recommend you take an over-the-counter (OTC) H-1 antihistamine, which will block the effect of inflammation-causing histamines in your body. This will also help control the uncomfortable rash and itching that occurs with hives.

Usually, doctors suggest patients with hives take non-drowsy antihistamines daily for several weeks. Some common examples of these types of antihistamines include:

• Cetirizine (Zyrtec)
• Loratadine (Claritin)
• Loratadine (Alavert)
• Fexofenadine (Allegra)

Keep in mind that some antihistamines, like diphenhydramine (Benadryl), can cause drowsiness, an effect intensified by alcohol use. Some antihistamines also aren’t safe for use by certain populations, like pregnant women. Speak with a doctor to determine the best antihistamine option for you.

If antihistamines aren’t enough to keep your hives under control, there are other medications for hives, such as:

• Histamine (H-2) blockers, also known as H-2 receptor antagonists
• Oral corticosteroids, such as prednisone, to decrease inflammation
• Tricyclic antidepressants creams to help with itching
• Immune-suppressing drugs
• Asthma drugs, such as albuterol, along with antihistamines for any wheezing

If you have a history of hives accompanied by swelling of the tongue, lips, throat, or eyelids or difficulty breathing, a doctor may prescribe epinephrine (adrenaline) for you to keep with you at all times. These symptoms can be the sign of anaphylaxis, a serious allergic reaction, and if you are experiencing those symptoms you should go to the ER right away.

Treatment options for chronic hives

If you have chronic hives, your treatment will vary depending on the underlying cause. For example, if you have an autoimmune disease, that will need to be treated in order to prevent hives and other rashes. If you still experience hives, the provider might suggest an antihistamine or other medication to control symptoms.

Treatment options for stress-induced hives

For people who have hives due to emotional stress, it’s important to practice relaxation techniques that help the body cope with anxiety or other stressful experiences. Your doctor may recommend evidence-based stress treatments like:

• Psychotherapy
• Anxiety medication
• Deep breathing techniques
• Meditation
• Mindfulness journaling
• Exercise

At-Home Remedies for Hives

Avoiding triggers is the most effective method for preventing and improving hives. To reduce the discomfort caused by hives, you can try:

• Applying a cool compress or cold water to the affected area
• Wearing loose and light, non-irritating clothing
• Avoiding scratching the welts
• Choosing soaps and lotions for sensitive skin
• Taking an oatmeal bath
• Using mild laundry detergents
• Applying an anti-itch cream
• Avoiding foods that increase histamine production, such as tomato, fish, processed meat, chocolate, some alcohol, spinach, and strawberries

When to See a Doctor

Some people experience hives as part of a serious allergic reaction known as anaphylaxis, which requires immediate medical care. Along with a rash, anaphylaxis includes other symptoms such as:

• Trouble breathing
• Swelling of the lips, eyelids, and tongue
• Dizziness or lightheadedness
• Nausea and vomiting
• Cold and clammy skin
• Fast heart rate
• A sudden feeling of intense anxiety

If you have any of these symptoms, or swelling in your throat that’s causing you to have difficulty breathing, seek emergency care or call 911 right away. You should also seek emergency medical care if you start developing an allergic reaction - even a mild one - but have a history of anaphylactic reactions. If you have a history of anaphylaxis, you should be prescribed an epinephrine auto-injector (EpiPen) and have it with you at all times.

For hives that aren’t causing emergency problems but are persistent (lasting several days or weeks), you can speak with your primary care provider or a K doctor for further information on how to manage your symptoms.

How K Health Can Help

It’s important to know the difference between acute hives and a real medical emergency. Did you know you can get affordable primary care with the K Health app? Download K to check your symptoms, explore conditions and treatments, and if needed text with a doctor in minutes. K Health’s AI-powered app is HIPAA compliant and based on 20 years of clinical data.