What is Skin Hives?
Hives (urticaria) is a skin condition characterized by red, raised bumps that may or may not itch. Typically, hives are an immune-system response to contact with an allergen. However, a person may break out in hives for other reasons, such as stress. An acute case of skin hives lasts 6 weeks or less. Most of the time they go away after 24 hours, but new hives may appear on top of the old ones, especially if the trigger for them is still present. If the condition persists for more than 6 weeks, it is considered a chronic condition.
What Causes Hives?
Anyone who has broken out in hives knows how unpleasant they can be. Not only are they unsightly, but hives often itch and scratching them typically only aggravates the condition. Skin hives is caused by the release of histamine and other inflammatory agents in the body. These agents cause fluid to leak from the blood vessels. When this occurs on a superficial level, hives break out on the surface of the skin. When the leakage occurs deeper in the body, angioedemia (hives under the skin or on internal organs) can occur.
There are a number of things that can trigger a break out of hives.
If a person is allergic to certain foods, he or she can break out in hives after coming into contact with the trigger. Shellfish and nuts are the most common food allergies in adults. For children, shellfish, eggs, soy, wheat, and peanuts are the most common food allergens. Consuming foods that you are allergic to can cause angioedemia, and you should seek immediate medical attention if that occurs.
Pet dander, pollen, insect stings and bites, and latex are other things that can induce skin hives if the person is allergic.
- Drugs and Medication
Hives are a side effect of certain medications. If you break out in skin hives after starting a new medication, it is best to talk to your healthcare provider about an alternative. Additionally, a person going through drug or alcohol withdrawal may break out in hives due to the stress of the event and/or the detoxification process.
There are some people who are allergic to exercise, and you may be one of them if you break out in hives, experience a shortage of breath, itch, or your blood pressure drops 5 to 10 minutes after starting to exercise. The condition is called exercise-induced anaphylaxis. Some people only experience symptoms when they exercise within half an hour after eating specific foods like shellfish.
Exercise-induced anaphylaxis differs from cholinergic urticaria because it only occurs when the person exercises. With cholinergic urticaria, hives develop after the person participates in any activity that increases his or her core body temperature, such as taking a hot shower.
- Environmental Elements
Exposure to environmental elements like cold temperatures, heat, the sun, and water can induce hives. Hives caused by heat, solar energy, and water are rare, but cold-induced hives are somewhat common. After coming into contact with the trigger, hives may develop within a few minutes to up to 18 hours afterwards.
Physical and emotional stress can induce the formation of skin hives. Typically, the hives are small – about 2 to 3 mm – tend to appear on the upper arms and chest, and only lasts for 60 to 90 minutes.
Although rare, a person can develop angioedema within 2 to 4 minutes after coming into contact with vibrations. However, the condition only lasts for about an hour. People with this condition should avoid vibratory stimulants, which can be difficult in technologically-advanced areas.
People with this type of urticaria will develop hives immediately or approximately 6 hours (delayed urticaria) after pressure is applied to the skin. The hives typically follow the pattern of the object that applied the pressure. For example, a person that scratches a word into his or her arm will develop hives in a manner that makes the word appear on the skin.
Anything that applies pressure to the skin can trigger hives including tight clothing, leaning against an object, and sitting on a hard surface. The chest, hands, legs, face, feet, and buttocks are the most common places affected by this condition.
- Other Causes of Hives
Contact with chemicals and parasitic infections like fascioliasis can induce skin hives. It is believed that chronic idiopathic skin hives may be caused by an autoimmune disorder where the body begins to attack itself. Although commonly mistaken for hives, the rash caused by contact with poison oak, ivy or sumac is a form of contact dermatitis.
What Are the Symptoms of Hives?
There are many skin conditions, like contact dermatitis, that are mistaken for hives. It is important to know the symptoms of hives to ensure your skin condition is diagnosed correctly and you receive the right treatment. The most common signs of hives are:
- Raised, red or pink welts
- Swelling that subsides within 24 hours
- Welts can be grouped in one spot or spread out over a large area
- Itching, stinging, or burning sensation depending on the trigger
Hives can be an acute condition (lasting less than 6 weeks) or a chronic condition (lasting more than 6 weeks). Typically, people who remain in contact with the trigger are more likely to experience chronic urticaria.
Angioedema are hives that develop underneath the dermis (skin) or on the internal organs. When angioedema occurs on the skin, it causes rapid swelling of the subcutaneous and submucosal tissues, the mucosa, and the dermis. Itching and pain may accompany the swelling, but compression of nerves may also cause reduced sensations in the area.
Angioedema that occurs on internal organs may be more difficult to diagnose depending on the location. However, if it occurs in the throat or mouth, the swelling will quickly become apparent and person affected will require immediate medical attention to avoid suffocation.
- Urticarial Vasculitis
This is a more serious form of hives characterized by individual hives that cause bruising during the healing process, last longer than 24 hours, and are painful. It is caused by inflamed blood vessels and may be accompanied by a burning sensation or itching.
These welts appear in a linear fashion typically minutes after the skin is stroked, scratched, rubbed, or slapped. The swelling may present with itching. Although this type of hives usually goes away after 15 to 30 minutes, it can persist for several days.
Is Hives Contagious?
When a person is suffering from a skin problem, it can make the people around him or her uncomfortable. Most likely this is due to a concern that the skin condition is contagious. Although hives can be unpleasant to look at and endure, they are not contagious.
Skin hives (called urticaria) are the body’s reaction to an internal or environmental trigger, so you cannot get hives by coming into contact with another person that has them. These triggers can be anything from a food allergy to medication to stress. When the body is exposed to the trigger, it releases histamines and other inflammatory agents into the blood that cause the blood vessels to leak fluid. Hives will break out on the dermis if this occurs on a superficial level and on internal organs if it occurs deeper in the body.
Although there are different types of hives, none of them are contagious including chronic hives and angioedema. Skin hives are common, though, and about 20% of the population has experienced them at one time or another in their lives. This means that you can develop hives if you come into contact with a substance that triggers the allergic reaction in your body. In some cases, skin hives are idiopathic, meaning there appears to be no cause for them. However, research indicates that idiopathic hives may be caused by an autoimmune disorder.
Are Hives Dangerous?
While hives can be uncomfortable and itchy, they are usually common and occur to quite a number of people. The pain usually lasts for a couple of hour and should go away on its own. Some types of hives may cause pain more than twenty – four hours and may also cause bruising once it heals. This is a more serious condition and should be treated right away. There are also rare cases which causes the airways to swell. This causes asphyxiation, and requires medical treatment immediately.