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What are the Most Common Causes of a Hives Rash?

Hives, or urticaria, often flare up due to allergies, stress, or certain medications, triggering itchy, red welts on the skin. Infections and exposure to extreme temperatures can also provoke this immune response. Understanding the triggers is key to managing symptoms. Have you ever wondered how your daily habits might influence your skin's reaction? Let's explore this further.
Henry Gaudet
Henry Gaudet

A hives rash, also known as urticaria, is most often associated with an allergic reaction, and in many chronic cases, allergies are responsible. There are other possible causes, and short-lived bouts of hives are often caused by viral or bacterial infection. Heat, cold or constriction from tight clothing or jewelry might irritate the skin and cause hives to form. Hives also might be a symptom of medical conditions such as thyroid, kidney or liver dysfunction, and chronic cases should receive medical attention to determine the cause.

Hives are raised, itchy, red welts on the skin. These welts often appear in clusters, and although they can appear anywhere on the body, they are often observed on the face and extremities. Hives appear quickly, and individual welts might clear quickly while new ones form, making it appear that the hives rash changes shape and location. The welts occur when the capillaries just under the skin leak fluid, causing the region to puff up and swell.

Allergic reactions commonly cause hives. When an allergen is introduced to an allergy sufferer, the body responds by producing histamines. These histamines trigger the capillary leaking that causes the welts to form.

A hives rash.
A hives rash.

Allergy sufferers are exposed to allergens through ingestion, inhalation or skin contact. Medications such as antibiotics, painkillers and anticonvulsants are all potential allergens. Foods such as nuts and shellfish are closely associated with allergies, but nearly any food can potentially trigger allergic reactions, including a rash. Pollen, mold and animal dander might cause similar results when inhaled. Examples of exposure through skin contact include animal bites and scratches or handling of plants.

Another likely cause of hives is infection. Viral, bacterial and fungal infections might each be responsible for producing a hives rash. Parasites such as pinworms and giardia can also cause hives.

Heat and sweat can cause skin irritation, resulting in hives. Tight clothing and jewelery can constrict the skin and trap sweat, with similar results. Low temperatures might also irritate the skin, and cold is as likely as heat to produce hives.

Many sources of hives cause irritation directly to exposed skin. Hives can appear anywhere on the body, but rashes are especially likely on the exposed skin of the face and extremities. The location of the rash might offer a clue about the source.

Allergies to shellfish, like oysters, can cause hives.
Allergies to shellfish, like oysters, can cause hives.

Frequently, no definitive cause of a rash can be found. Experts agree that viral infection usually is the most likely cause for these cases, especially when the rash spreads to other patients within a short time. Other common causes such as allergens, mold and heat, though less likely, should not be ruled out when attempting to identify the source of the hives rash.

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Discussion Comments


There are certain medical conditions that cause hives, even when there is no allergen. For example, disorders of the immune system may be responsible for these types of reactions. But these are not as common as allergic skin rashes that itch. Most doctors will not think of such disorders first when they see a hives rash.

Hives is a sign that the body was exposed to something that it is sensitive to. Sometimes it's a clear-cut allergy. Other times it's just a sensitivity and the rash is fairly mild or temporary.

For example, certain drugs, such as antibiotics may cause a hives rash in some people. This type of drug induced rash shows up a week or more after the drug treatment starts. It usually goes away on its own and is not dangerous. Sometimes though, the hives occurs quickly and is accompanied by other symptoms like swelling. In these cases, it's not just a sensitivity but a severe allergy that must be treated immediately.


@bear78-- Hives from contact with something is common. But I think that this is also considered an allergic reaction. Hives wouldn't occur if the person was not allergic to the substance that he came in contact with. Hives is almost always caused by an allergen.

If you are talking about contact dermatitis, I think that's a different thing, although an allergic reaction might be responsible for that as well. I'm not sure though, you might want to ask your doctor.


What about hives due to physical contact with something? Is this common? What types of things can cause this type of urticarial rash?

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    • A hives rash.
      By: Rob Byron
      A hives rash.
    • Allergies to shellfish, like oysters, can cause hives.
      Allergies to shellfish, like oysters, can cause hives.
    • Anti-itch cream can be applied to alleviate the symptoms of hives.
      By: picsfive
      Anti-itch cream can be applied to alleviate the symptoms of hives.