Gary W. Cole, MD, FAAD
Dr. Cole is board certified in dermatology. He obtained his BA degree in bacteriology, his MA degree in microbiology, and his MD at the University of California, Los Angeles. He trained in dermatology at the University of Oregon, where he completed his residency.
Melissa Conrad Stöppler, MD
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
In this Article
- Hives facts
- What are hives (urticaria) and angioedema?
- What causes hives and angioedema?
- What are the different kinds of hives?
- What are the symptoms and signs of ordinary urticaria (ordinary hives)?
- What are the causes of ordinary hives?
- What are the causes of chronic hives?
- Are there other conditions that mimic hives?
- What is the treatment for hives?
- What is the prognosis of hives?
- Find a local Dermatologist in your town
What are the causes of chronic hives?
Chronic hives (defined as lasting six weeks or more) can last from months to years. The evaluation of this condition is difficult, and allergy testing and other laboratory tests are only occasionally useful in such cases. The accurate evaluation of this condition requires the patient to give his or her physician precise information regarding their complete medical history, personal habits, and oral intake. Occasionally, it may be necessary to limit specific foods or drugs for a time to observe any affect upon the skin condition. Certain systemic disease and infections may occasionally present in the skin as hives. Rarely, common environmental provocations such as sunlight, water, cold, heat, exercise, and pressure seem to induce hives. If an inciting cause can be determined, then specific treatments for that condition ought to be effective, or in the case of food or drug allergy, strict avoidance would be necessary. There are additionally rare forms of chronic urticaria that are produced when the patient makes antibodies against molecules on the surface of their own mast cells. There are tests available to identify this type of hives.
Physical urticaria is a type of chronic urticaria produced by physical stimuli. By far the most common form is dermographism, which literally means "skin writing." This is an exaggerated form of what happens to anyone when their skin is scratched or rubbed: a red welt appears at the line of the scratch. In dermographism, raised, itchy red welts with adjacent flares appear wherever the skin is scratched or where belts and other articles of clothing rub against the skin, causing mast cells to leak histamine.
Another common form of physically induced hives is called cholinergic urticaria. This produces hundreds of small, itchy bumps. These occur within 15 minutes of exercise or physical exertion and are usually gone before a doctor can examine them. This form of hives happens more often in young people.
Are there other conditions that mimic hives?
There are other rashes that may look like hives but the fact that they remain stable and do not resolve within 24 hours is helpful in distinguishing them from hives. Such rashes may need to have a small specimen of skin removed and examined under the microscope (biopsy) to accurately determine the nature of the skin disease.
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