What are the common causes of hives?
Allergies only cause about 5 to 10% of chronic hives cases. When allergies cause chronic hives, is usually to blame. Pollen, mold or only rarely cause chronic hives.
Having hives may cause , but by itself does not cause hives.
Allergic reactions, such as to foods and medicines, can also cause hives. Hives that occur as a result of a food allergy almost always appear within a few minutes to a few hours after eating the food.
An allergic reaction can cause hives, as can temperature extremes, stress, infections, or illnesses. In some cases, hives are accompanied by angioedema, a condition that can cause swelling around the eyes, lips, hands, feet, or throat. Very rarely, hives and angioedema are associated with an allergic reaction that involves the whole body or .
The of hives include itching in most cases, swelling of the area, red welts that look much like a mosquito bite. If you have any of these symptoms, you may have hives. Most doctors when presented with hives, will try to test to find out the allergen that is responsible for the case. If the allergen simply cannot be found, such as in , only the symptoms are treated. Many doctors will give antihistamines because histamines are released into the system and this is what causes hives to form, but these commonly given antihistamines and corticosteroids only treat symptoms, not the causes. If you or your child has a life threatening case that causes constricted breathing, epinephrine is commonly given on the spot. Regardless of what causes your hives, most people find that eliminates their hives symptoms and outbreaks faster than any other medication on the market. Please see our page for more information. Most of the time the causes of hives remain unknown. There are certain things that are common causes though, or what are called triggers. These include, but are not limited to:Chronic episodes of urticaria last more than six weeks. In most cases, the cause of chronic hives will not be identified despite testing. Half of the patients have antibodies (proteins) that attack the mast cell (allergy cell). This triggers chemicals such as histamine to be released which causes the hives and itching. Even though hives are associated with other autoimmune conditions such as thyroid disease, treating the other condition doesn’t cure the hives. Rarely, chronic urticaria has been associated with cancer. In most cases of chronic urticaria, the hives will gradually disappear over time.What are the different types of urticaria?
Acute episodes of urticaria last for six weeks or less. Acute urticaria can be due to infections foods, medications, insect stings, blood transfusions and infections. The most common cause of hives is infections. Foods such as eggs, nuts and shellfish are common causes of urticaria. Medications such as aspirin and antibiotics (especially penicillin and sulfa) also are common causes of hives. Infections causing hives include the common cold, and other viral infections. In most of these cases, when the reason for hives is removed or avoided, the hives resolve. Dozens of infections can cause hives, including throat, stomach, and genital or urinary () tract infections; fungal infections; mononucleosis; and hepatitis. The common cold often causes hives in children. Hives aren't directly caused by the infectious organism, as in chickenpox or cellulitis. Rather, they're caused by "friendly fire" from the human body's own defences.Chronic urticaria should be evaluated by an Allergist/Immunologist. This specialist will take a detailed personal medical history, familys’ medical history, and medication history. In some cases you may require tests to analyze blood and urine. It is rare for a food to cause chronic hives. The specific cause of hives is rarely identified. If you have chronic hives, your doctor will probably examine you for signs of other medical problems that can cause hives to appear, such as lupus and rheumatoid arthritis. Your doctor may ask for routine tests for these conditions. Blood tests generally reveal very little about hives. In many cases (at least half), the cause remains a mystery. It usually doesn't matter, because hives are a brief, solitary event for most people. Your doctor may ask you to keep a record of what you eat and your activities to try to pinpoint the cause.For some people, the cause of hives that appear at night is more directly related to something that happens in the moments during or before sleep. For example, individuals may have sheets on their beds made of a material they are allergic to. It’s also possible for a person to expose himself to some chemical during his preparations for sleep, such as a particular soap used while showering.