Hives can be frustrating; the itching is persistent and annoying. More frustrating, however, is the itching of the mind - the mystery behind what is causing this affliction. Unfortunately, it's not uncommon to be left with no answers as to the cause! Then, to add to the mystery, hives can leave just as insidiously as they arose!
Is It Hives?
What They Look Like: Hives (also known as urticaria) are raised bumps caused by irritation in the upper layers of the skin. Their appearance can be pale or red in color with the usual size being one to two centimeters in size. While hives are often round or oval, they can be other shapes or confluent in a larger mass.Hives can come on the skin of any area of the body. Scabies bumps, while also itchy are usually linear and more intense on the webs of the fingers and toes. If blisters are present, this is usually a contact dermatitis as seen with poison ivy rather than hives. If the rash is only on exposed parts of the body, think bites (mosquitoes or fleas).
What They Feel Like: They are always itchy. Sometimes hives can occur with inflammation in the deeper layers of the skin causing swelling and pain. If the rash isn't itchy, it's probably not hives. Remember, though, that not all itchy rashes arehives.
Types: Hives (or urticaria) are classified as acute or chronic.
- Acute Urticaria: Acute urticaria comes on quickly in response to some stimulus. The hives usually resolve in hours but can persist for up to six weeks. When present with swelling, primarily in the lips, tongue, or airways, the situation could be related to anaphlaxis, a potentially life-threatening allergic reaction.
- Chronic Urticaria: If the hives persist for longer than six weeks they are classified as chronic urticaria.
How the Body Makes Hives
Hives are triggered by the release of a substance called histamine by an immune mechanism. Mast cells (specialized white blood cells) are an important part in this mechanism. They contain pockets of histamine, and, when stimulated by a trigger, they release it into the tissue, creating an itchy hives response in the skin. In other areas, histamine produces the symptoms of allergies (mucous production, itchy-watery eyes, fatigue) and asthma (wheezing).
What Triggers Hives?
When hives are present it is important to try and identify the trigger.
Acute Urticaria Triggers.
In acute urticaria the offending agent is easier to identify. Common triggers include:
- Insect venom
- Infections (from the common cold to bladder infections).
Occasionally, simple contact with a certain stimuli can cause hives as well. This includes:
Chronic Urticaria Triggers.
In the case of chronic urticaria, a cause is usually less forthcoming. In fact, the cause is actually only found in about 10 to 20 percent of cases. Certain disease states are a rare cause such as:
- Thyroid disease
Hives that are present less than six weeks are considered acute while those present longer are chronic. Chronic urticaria is occasionally a herald of a more serious disease, and, for this reason, a healthcare provider should be consulted and blood tests ordered. Treated or not, more than one-half of people with chronic urticaria will have resolution of symptoms within one year.
What Are Treatment Options for Hives?
Avoid Triggers: The most important treatment for hives involves avoidance of the trigger(s).
Antihistamine: Antihistamines are the mainstay of conventional medical therapy if avoidance is not possible. Antihistamine medications can block the release of histamines by the mast cells. Keep in mind, however, that the histamine that is already circulating will be left to do its work. In other words, the results are not immediate. Antihistamines can be used effectively in prevention if exposure to a known trigger is likely.
Epinephrine: If anaphlaxis is present with rapid onset of swelling and trouble breathing, administer an injection of epinephrine (epi pen), if prescribed, or call 911, as this can be life-threatening.
Hives are annoying and frustrating. The rash is itchy, and it sends people on a quest to find the offending agent, often only to come up empty handed. Rarely, hives are a herald of a life-threatening allergic condition called anaphlaxis. Mostly, though, they are related to a certain trigger that contacts the body externally or is ingested. If you have hives, you are not alone as 20% of people will experience hives at some point in their lives.
More information can be found here.