Hives that come and go over extended periods of time are considered to be chronic hives. All forms of hives, both chronic and acute can come in waves making them appear to spread from one body part to the next or clear and then return. Hives that come and go are thus common and are a telltale sign of this type of rash. Patients should keep in mind however, while a case of hives can last anywhere from an hour to several weeks, individual urticaria welts should not last for more than 24 hours.
Hives That Come and Go: Chronic Hives
Hives are considered chronic when any given episode lasts for more than six weeks. Unlike acute cases of hives that are usually caused by an allergy to foods, food additives, medication, or stings and bites, chronic hives tend to be without a known origin and are termed idiopathic urticaria. In 50% of these cases the urticaria welts are cause by a histamine reaction within the body resulting in the itchy red welts. In other cases of idiopathic urticaria immune or hormonal functions are to blame and often point towards an infection or disease unrelated to the skin and allergies. In some rare cases of chronic hives welts may last longer than 24 hours causing pain rather than the common itching. When the welts clear they can leave a bruise on the skin. While not all cases of painful hives are caused by vasculitis (inflammation of the blood vessels, http://www.mayoclinic.com/health/vasculitis/DS00513), it is the most common cause of this form of hives.
Dealing with Hives That Come and Go
If you suffer from hives that come and go for more than six weeks you should book an appointment with your allergist or an immunologist so that a series of tests can be run to discover possible causes including any underlying illness. When you visit your doctor it is important to share with him/her your full family medical history, any medications (including vitamins) you are taking, and information about your home and work environment, including the products used in those places. Depending on your particular case a series of test may be necessary. Your allergist may recommend a skin allergy test to determine if you are coming into contact with or ingesting an allergen. Other test may include a skin biopsy, to determine if you have vasculitis, and blood and urine samples. As frustrating as it may seem only 20% of hives cases can be diagnosed with a cause, making patient comfort and itchiness relief the primary treatment. Anti-histamines, steroids, and topical creams are often the best method to treat hives.
