Many people are already familiar with hives – sudden outbreaks of red bumps on the skin that typically burn, itch, or sting. Less familiar, though, is hives’ close cousin angioedema. It similarly causes swelling of certain issues within the skin.
Angioedema and hives are connected because they are similar reactions to the same underlying cause, which is a release of chemicals called histamine within the skin. In many cases, histamine and other chemicals are a byproduct of the body’s mast cells as they perform their task of eliminating allergens (any substance that elicits an allergic reaction).
Histamine can be produced in other ways than combating allergens. Some medications, as well as irritation caused by sunlight, and various unknown sources can also spark mast cells into releasing histamine.
Regardless of what caused the release, histamine can cause angioedema and hives by dilating the small blood vessels within the skin, causing fluid to release from them. This quickly leads to swelling. It also leads to gastric acid secretion and causes specific smooth muscles to contract.
Hives (formally known as urticaria) are light red welts that can develop anywhere on the body in patches as small in size as a pencil eraser or as big as a dinner plate. These patches of red sometimes overlap to create the appearance of a larger area, known as a plaque. No matter how big or small, the symptoms of hives tends to dissipate within a few hours, but sometimes they will remain for up to or over a day.
Generally, the symptoms of angioedema lasts longer than urticaria, however the swelling tends to fade within 24 hours. Common symptoms include severe swelling around the lips and eyes, and occasionally swelling of hands, feet, and genitals.
In rare cases, the swelling is so intense and prolonged that it results in disfiguration of tissue. It may even cause swelling in the tongue, throat, or lungs, blocking airways and making it difficult to breathe. If this occurs, the victim is in serious danger and should seek medical treatment immediately.
Types of Angioedema and Urticaria
Physicians generally categorize angioedema and urticaria in the following classifications:
- Acute urticaria is hives that disappears within six weeks. The usual causes are medications, foods, latex, or infections, however internal diseases and insect bites may also be responsible. The most frequent foods that elicit hives are fish, nuts, fresh berries, and tomatoes. Medications can also lead to angioedema and hives, such as aspirin, high-blood-pressure medications (ACE inhibitors), nonsteroidal anti-inflammatory medications (NSAIDs) like ibuprofen, and pain killers like codeine.
- Chronic angioedema and hives lasts six weeks or longer. The source of these kinds of reactions are much harder to determine than acute types. As a result, the cause is often unknown. In fact, more than 80% of cases of chronic urticaria are by an unknown cause.
- Lastly, physical urticaria are hives outbreaks caused by direct physical contact to skin from exposure to heat, cold, sun, pressure, exercise, sweating, vibration, and other sources. These hives tend to develop at the area of stimulation and scarcely elsewhere. Most appearances in this category are visible within an hour following exposure.
Diagnosis and Treatment
The best method of treating angioedema and hives is for your physician to determine the primary causes and for you to then avoid them. Unfortunately, it is quite a difficult task to determine the specific triggers. Your doctor will need to conduct an extensive interview asking you many questions in addition to performing some tests.
Since there are no specific tests for angioedema and hives, the types of tests performed will be based on your medical history, as well as a rigorous examination by one or multiple specialists. Additionally, skin tests may be conducted to determine the substances which you may be allergic to. Frequent blood tests are performed to rule out systematic illness as a cause of your body’s tendency to produce histamine.
If your condition is chronic, your doctor will most likely prescribe an antihistamine that alleviates the symptoms you experience. These medications are most effective when ingested regularly to stop swelling. For intense outbreaks, injections of a cortisone-based medication or epinephrine (adrenaline) may be required.
Afterwards, oral corticosteroids may be prescribed if antihistamines fail to alleviate symptoms. In most cases, doses of antihistamine medication will be increased beyond amounts used in other similar conditions (such as when treating hay fever or allergic rhinitis).
Various medications can be prescribed for individuals suffering from “antihistamine resistant” urticaria or angioedema that can remedy the conditions. While waiting for symptoms to fade away, here are some tips to make the wait more bearable:
- Stay away from warm water; use lukewarm instead.
- Remain in a cool environment.
- Wear lightweight, loose-fitting clothes.
- Use gentle, mild soap.
- Place wet cloth or cool compresses to affected areas.
When to seek medical assistance
Most cases do not require any medical help and will fade away on its own. However, you should visit a doctor if:
- Your hives remain for over 24 hours.
- They frequently appear for over a month.
- You experience symptoms of anaphylaxis (a life-threatening allergic reaction) or angioedema.
Go to the emergency room if any of the following symptoms are present during your angioedema or hives outbreak:
- Tightness in the chest.
- Difficulty breathing.
- Swelling of the lips, tongue, or face.