Sometimes they sting or feel painful. In most cases, hives are triggered by an allergic reaction to food, medication, or an environmental irritant.
For many people, hives are acute (short-term) and improve with allergy medications. Most rashes disappear on their own. However, chronic (long-lasting) hives — or hives that occur alongside a severe allergic reaction — are more serious and require medical attention.
What causes hives?
Hives typically develop due to an allergic reaction to something you’ve eaten or come into contact with. During an allergic reaction, the body releases histamines into the bloodstream. These chemicals help defend against infections and foreign substances — but in some people, they also trigger itching, swelling, and other hive-related symptoms.
Common allergens that can cause hives include pollen, medications, foods, animal dander, and insect bites.
Hives can also appear for reasons unrelated to allergies. Stress, tight clothing, exercise, infections, and certain illnesses can all lead to hives.
Exposure to extreme heat or cold, or irritation from excessive sweating, may also play a role. Because so many triggers are possible, the exact cause often remains unknown.
Who is at risk?
People with known allergies are more likely to develop hives. You may also be at higher risk if you are taking medication or are unknowingly exposed to allergens like pollen or certain foods. Illness and infection can also increase susceptibility.
Symptoms
Chronic hives may involve:
– Groups of raised welts (weals) appearing anywhere on the body
– Welts that may be red, purple, or skin-colored depending on your skin tone
– Welts that shift in size and shape, and come and go repeatedly
– Intense itching (pruritus)
– Painful swelling (angioedema) around the eyes, cheeks, or lips
– Flares triggered by heat, stress, or exercise
– Symptoms that last more than six weeks and recur for months or even years
Finding relief: Treatment options
The first step is determining whether you truly have hives. Most of the time, a doctor can diagnose them through a physical exam by observing the characteristic welts.
If an allergy is suspected, blood tests or skin tests may be performed to identify the trigger.
Mild cases not linked to allergies or underlying health issues may improve with simple home remedies. A doctor may recommend:
– Taking antihistamines such as diphenhydramine (Benadryl) or cetirizine (Zyrtec)
– Avoiding scratching or irritating the skin
– Staying away from hot water, which can worsen symptoms
– Taking a cool or lukewarm bath with colloidal oatmeal or baking soda
Seek emergency medical care
Consult a healthcare professional if your hives are severe or last longer than a few days.
While chronic hives do not usually lead to life-threatening reactions, hives that occur as part of a severe allergic reaction require immediate emergency care. Signs of anaphylaxis include dizziness, difficulty breathing, and swelling of the tongue, lips, mouth, or throat.
