Definition & Overview
Hives, medically known as urticaria, are red, smooth, and oftentimes itchy, raised bumps that form on the skin and suddenly appear in different shapes and sizes. They are fairly common and go away on their own even without medical intervention. They can change in size, spread, disappear, or even reappear in another place rapidly, just in a matter of hours.
About 20% of the population is bound to develop hives at least once in their life. Urticaria can appear anywhere in the body, including the face, chest, back, lips, eyelids, tongue, ears, and throat. It seems to be more prevalent in women than men. The occurrence of hives can be more serious in some people, sometimes accompanied by swelling and build-up of fluid in certain affected body parts - a condition called angioedema.
Causes and kinds of hives
The main cause of hives is yet to be identified despite advances in research in the field. However, hives are believed to be an allergic reaction to certain allergens. Allergic hives form as a response to histamine, which is released by specialized cells into the blood vessels to counter-attack an allergen in the body. When this happens, blood plasma leaks out of the small blood vessels, resulting in pale bumps or plaques that appear on the skin.
Allergic hives can be attributed to certain triggers, which may include:
- Chemicals in certain food or food supplements
- Insect stings or bites
- Animal dander (usually cats)
- Exposure to pollen and certain plants like poison ivy or poison oak
- Exposure to heat UV rays of the sun
- Reaction to certain medications (some common ones are morphine, aspirin, codeine, and NSAIDs like ibuprofen)
- Emotional stress and anxiety
- Extreme cold
- Excessive perspiration
- Physical exercise, usually in young adults
There are a few general types of hives which are as follows:
Acute Urticaria - Typically lasting less than six weeks, acute hives are usually caused by food (such as eggs, chocolate, nuts, fish, berries and milk), food preservatives, medications, insect bites and infections.
Chronic Urticaria - Usually lasting more than six weeks, the main cause of chronic hives is difficult to identify. Causes may include underlying conditions such as hepatitis, infection, thyroid problem or even cancer.
Physical Urticaria - This type of hives is often caused by direct stimulation of the skin - such as due to cold, heat, UV exposure, and sweating. The bumps usually appear in the part of the skin that was physically stimulated.
Angioedema - Angioedema is a condition when the onset of rashes is accompanied by visible swelling. Often affecting the eyes, lips, hands, feet, and genitals, it’s typically accompanied by burning hot and painful sensation in the swollen area. Swelling in the throat, air sacs in the lungs, and tongue is indicative of a serious condition that requires medical attention.
Key symptoms of Hives
Hives are red, oftentimes itchy bumps or rashes that flare-up suddenly on the skin without warning and for no specific reason. The flare-ups suddenly appear, itch for a few hours, possibly swell, and then go away after a period of time. The appearance of the rash is its main symptom. Hives can last from a few hours to days and even weeks. When pressed, the center of the red rash turns white (blanched).
Symptoms of chronic hives can be troublesome and uncomfortable that they can make regular daily activities and sleeping difficult. In severe cases of angioedema, hives cause dangerous swelling in affected areas that can block your airways, leading to a medical emergency.
Who to See & Types of Treatments Available
If you suspect that you have hives, it is best to see your general practitioner immediately. This is especially true if you experience any of the following:
- Recurring attacks of hives lasting for more than four weeks
- Itchy and burning rashes in the throat that hamper your breathing and swallowing
- Hives accompanied by cough, cold sweats, dizziness, nausea, and low blood pressure
- Hives accompanied by difficulty in breathing
- Symptoms of angioedema, especially in the head or neck
A dermatologist is the best specialist to see for any skin condition like hives. The dermatologist can easily diagnose hives just by observing the key symptoms and the bumps on your skin. What remains difficult though, is determining the causes or triggers of your hives. It becomes even more difficult to determine the causes of chronic cases of urticaria. Your dermatologist can also refer you to an allergist.
In order to determine the underlying cause of your hives, the dermatologist or allergist will ask questions which may include previous food intake, medications taken, activities performed for the past day(s), and your family history. Some tests may also be conducted and may include the following:
- Allergy tests (skin or blood work) to narrow down possibilities
- Blood tests to rule out infection and other illness
- Skin biopsy for severe symptoms and chronic skin conditions
There are several treatment methods available for alleviating hives. For mild to severe cases of urticaria, first-in-line treatment is non-sedating anti-histamine medications such as loratidine or cetirizine. These medications can effectively relieve swelling and itchiness. Your dermatologist can also suggest a combination of other methods, among which include:
- The use of cortisone creams (usually for short-term use) to relieve itchiness
- Application of antibacterial creams or ointments like Dapsone to prevent or control infection
- Anti-inflammatory medications to fight inflammation and swelling
For severe cases of hives, immediate injection of epinephrine might be necessary.
There are also effective home remedies for hives that patients often find very useful in relieving discomfort. Application of cold, wet compresses to the affected areas, taking comfortable cool bath, and wearing smooth-textured loose clothing are among them. While hives are easily controlled, it is still very important to determine the cause and avoid its triggers. Boosting the immune system by eating the right kinds of food and avoiding stress through nerve-calming techniques like yoga and medication can also prevent hives from recurring.
- American College of Asthma, Allergy and Immunology: "All About Hives.” http://acaai.org/allergies/types/skin-allergies/hives-urticaria
- American Academy of Dermatology: “Hives." https://www.aad.org/dermatology-a-to-z/diseases-and-treatments/e---h/hives
- MedlinePlus Medical Encyclopedia: “Hives." http://www.nlm.nih.gov/medlineplus/ency/article/000845.htm