What Are Hives?
Hives, also known as urticaria, are when the skin becomes itchy with raised white areas (wheals) surrounded by redness.
Hives occur when histamine and other chemicals are released in the body causing blood vessels to dilate and fluid to leak into the skin.
Hives can last variable amounts of time. Those lasting less than six weeks are labeled acute. Hives lasting more than six weeks are called chronic. Of those patients with chronic hives, research has shown that 50% of patient’s hives resolve in 3-12 months, 20% resolve in 12-36 months, and 20% resolve in 36-60 months. In a few cases, patients can have hives for over 20 years. Once hives do resolve, up to 60% of patients can have a recurrence later.
What Causes Hives?
There are multiple triggers that cause hives including but not limited to, exposure to foods, insect venom or medications such as penicillin or morphine.
Although hives can occur from exposure to an allergen, they are not always due to an allergic reaction. There are different causes for what may be triggering your hives. Your healthcare provider can obtain a thorough history, physical exam and run necessary lab work to rule out the following:
- Cold urticaria – rapid onset of itching, swelling and redness to skin after exposure to cold. Can be restricted to certain parts of body exposed to cold.
- Pressure induced urticaria – gradual onset (4-6 hours) of swelling to skin where pressure has been applied to skin.
- Dermographism (means “write on skin” and is also known as factitious urticaria) – linear raised skin forms when skin is stroked. Itching often precedes rash and when skin is scratched it worsens.
- Solar urticaria – itching, redness and swelling of skin within minutes of exposure to sun light. Skin that is exposed is usually the only part of body affected.
- Cholinergic urticaria (also known as generalized heat) – severe itching and small, red hives with a “fried egg” appearance develop usually after hot shower, sudden change in temperatures, exercise, anxiety or sweating.
- Adrenergic urticaria – a “halo” of white skin around a small red spot develop usually due to stress
- Aquagenic urticaria – small red and swollen spots arise when contact with water is made despite the temperature.
- Infections such as viruses, bacterial infections, fungal infections and parasites can be causes of hives.
- Autoimmune Thyroid Disease – people with chronic hives have a higher tendency to have thyroiditis.
- Malignancies – though rare, malignancies can be the cause for hives.
More often than not, the cause of hives cannot be found. This is the case in up to 80% of patients. These cases are labeled “idiopathic”.
Who Gets Hives?
- 10-20% of the population will develop hives at least once in their lifetime.
- Acute urticaria is most common in young adults. Chronic urticaria commonly occurs in the middle aged population and more so in women.
- In the elderly population, hives are commonly caused by medications or malignancy.
How Do You Treat Hives?
Identify the possible cause for hives with your provider. A daily journal may be necessary to identify triggers for those with chronic urticaria. For those with idiopathic urticaria, control of itching, redness and swelling can be obtained.
The most important treatment is regular use of antihistamines. There are several different types of antihistamines, and you may be placed on a combination. It is important to find the right combination and dosages of medications in order to control hives.
You may wonder why your provider would put you on an acid reducer medication such as ranitidine. Medications such as ranitidine are in a class known as histamine 2 blockers. These medications can help to control hives by keeping the histamine from binding and causing a reaction at the cellular level.
Oral steroids may be required on occasion to suppress severe outbreaks of hives. However, we make every effort to avoid steroid dependence due to potentially serious side effects of long-term steroid use, such as osteoporosis, diabetes, poor wound healing, skin fragility, weight gain, and glaucoma.
Avoid any triggers such as foods, drugs, chemicals, cosmetics, or plants that are suspected to have caused your hives.
Hives can be difficult to treat, but rest assure your provider will work closely with you to tailor an individualized work up and treatment plan.