What causes hives?

Many causes. There are many causes of hives and these include infections, medications, bee/wasp stings, food allergies, environmental allergies, stress, cold temperatures, and exercise amongst other rarer causes. Oftentimes, hives are idiopathic, meaning no known cause. For further evaluation and management, consultation with a board-certified allergist is recommended.
Histamine release. Mast cell histamine release cause blood vessels to leak resulting in localized swelling (the bump of hives) & sensory nerves to fire giving the sensation or itching. These nerves trigger a local nerve reflex that increases blood flow (the redness of hives). Hives lasting <6 weeks are usually due to viral infection or allergy to foods or drugs. When >6weeks cause is may autoimmune or benign.
Usually allergic rxn. Usually it is caused by an allergic reaction, like contacting something you're allergic to touch. Consult your physician. Wishing you the best.

Related Questions

What causes hives?

Mast Cells. A special type of white blood cell (bodily defense system) called a mast cell contains the chemical histamine. When it is released in the and around the skin it causes the local swelling and itching we call hives or urticaria. This release of histamine can be caused by lots things like allergies, cold, exercise and even exposure to sunlight.
Broad answer. The causes of hives is very broad: foods, medications, other medical conditions to name a few. A detailed history is required to elucidate the cause of hives. It is not unusual to not find a cause of hives.
Many causes. There are many causes of hives and these include infections, medications, bee/wasp stings, food allergies, environmental allergies, stress, cold temperatures, and exercise amongst other rarer causes. Oftentimes, hives are idiopathic, meaning there is no known cause. For further evaluation and management, consultation with a board-certified allergist is recommended for evaluation and management.

What causes hives?

Everything. There are numerous things that will cause hives. Water, heat, cold, sun, drugs, infection are just a few.
Anything. Just about anything and everything can cause hives. Despite this we never determine the cause in many cases of chronic hives. Treatment is the main approach. For many people the hives eventually go away.

What causes hives... I have had them for 3 days now...

Allergy. Most common is an allergy to something you swallowed or touched. Medications, foods, detergents, insect bites, perfumes. Try antihistamines for few days, if not better see your dictor or an allergist.
Many Things. Hives can be caused by viral infections, allergies including food allergies, airborne allergies, or stress. In some studies up to 50% of patients with chronic hives (greater than 4 weeks) had no identifiable cause. If your symptoms don't improve see your doctor or an allergist for help.

What cause hives and inflammation?

Allergic reactions. Hives & angioedema (deep tissue inflammation) are most often caused by things ingested (like foods & medicines), stinging insects, and latex allergy. They can also be caused by an underlying condition such as an autoimmune condition or blood disorder. Sometimes they result from direct physical activation of the skin such with exercise & cold. In many cases the cause is difficult to pinpoint.
Non-allergic hives. Most patients for whom a cause of hives is found are allergic to a food or medication. If hives last for over 6 wk (chronic hives) 80% are not allergic and no cause is found. In children and many adults viral infections, e.g. Colds, stimulate histamine release in the skin causing hives. Some patients have antibodies against the cells in the skin containing histamine, leading to histamine release.

What causes hives besides allergies?

Several causes. The most common causes of hives are allergy, autoimmunity, and physical stimuli. Foods or drugs can cause hives - peanut and shellfish are common food allergens, and Ibuprofen and penicillin are common drug allergens. Some hives are due to physical stimuli such as cold, heat, pressure or stroking of the skin.

What causes hives and a swollen neck gland?

Hives. The cause for hives is often obscure unless one can specifically identify the trigger (food, drug, viral infection). In chronic hives, about 30% is considered an autoimmune process. As for swollen neck glands, any inflammation from the neck up may cause it. However, if present for more than a few weeks, one needs to consider a blood disorder such as lymphoma.