How Do You Know If You Have Hives?

For the past few years, summertime at my allergy practice has meant a sudden influx of patients with large, round or irregularly shaped, itchy, red welts breaking out in patches all over their bodies, or maybe just on their arms or legs. Often swelling of the lips or eyelids or ears happens too. Last week it was a law student trying to get through exams but unable to because of intense itching. Yesterday, it was the single Mom working 2 jobs that has been unable to sleep for months because she’s so busy scratching her hives until she bleeds all.
They’re both suffering from hives. The summer heat makes the misery worse. The seasonal pattern is likely related to the emergence of seasonal viruses.
I have a special empathy for hives sufferers because I am a sufferer also. For the past six months I’ve been struggling to gain control of the itchy welts on my legs and abdomen. When I was not up at night scratching, I was so exhausted and drowsy from the medications to control the itching.
Urticaria is the medical term for ‘hives’ or ‘welts’. Most patients think this condition is very rare, but urticaria actually affects 20% of the population at some point in their lives. We define urticaria as raised, itchy areas of skin that can be rounded or flat-topped but are always elevated above the surrounding skin. Bouts can last from several minutes to days/months. But no one hive should last for more than 24hrs. Hives cases often seem to present in clusters of cases or seasonally.
Medically, we feel that most hives are caused by immune cells in our skin, called mast cells, which have become ‘excited’. In their excited state they release chemicals like histamine that lead to swelling and itching. If these cells happen to be found in deeper layers of the skin they can lead to swelling. This swelling is called angioedema and most commonly occurs in eyelids, ears, lips, nose and joints. Angioedema occurs in about half the cases of hives.
Acute episodes of urticaria last for six weeks or less. Acute urticaria is more likely to be due to allergies to certain foods, medications, insect stings, and infections. Nuts and shellfish appear to be the culprit in many hives caused by food allergies and can occur at anytime in a person’s life – even after having eaten the food for years. Medications such as aspirin and antibiotics are also common causes of hives. Infections causing hives include the common cold, strep throat, infectious mononucleosis and hepatitis. In some cases the patient doesn’t even remember having the sniffles or a few days of a sore throat. Most cases of acute hives can be easily treated with anti-histamines or short courses of oral steroids. It is important to realize that when treating hives it is often not possible to stop the immune cells from releasing the offending chemicals. We simply try to block the effects of the chemicals, giving the immune process time to ‘burn itself out’. IT is important to weigh the risk of hives with the risk of using oral steroids for a non-life threatening condition. While simple hives are more annoying than life threatening, oral steroids can cause problems with blood pressure, blood sugar as well as bone loss with long term use.
Chronic episodes of urticaria last more than six weeks and sometimes can become a recurrent problem for years. 95% of recurrent and chronic hives cases are ‘idiopathic’ (a medical term that means there is no discernible cause). Because of those 5% of cases with a cause, it is worthwhile to see a physician to determine if any underlying disease is present. Chronic urticaria may be associated with thyroid disease (especially in women), liver disease, chronic infections, other autoimmune disorders (like rheumatoid arthritis, Crohn’s disease, etc) or very rarely, cancer. In most cases of chronic urticaria, the hives will gradually disappear over time. We often see a pattern of hives flaring in times of great life stress like death of a loved one or marital stress. Most cases of chronic hives can be controlled with combinations of oral anti-histamines – some non-sedating (Claritin, Zyrtec, etc) and some sedating (Benadryl). Rarely patients will require the use of long term oral steroids and or other immune-suppressants.
Some cases of hives seem to be caused by a physical trigger. Some common triggers for this condition include sunlight, pressure, cold or heat. Often identifying the physical trigger and avoiding it can be helpful. For example, patients with solar urticaria develop hives after exposure to specific wavelengths of light. Treating these patients with sun block or fabrics that block specific wavelengths of light can be effective.
In some cases of hives, the cause is obvious and simply requires some detective work on the part of the patient and physician. In some cases, the cause cannot be identified. Single episodes of uncomplicated urticaria usually do not require extensive testing. Chronic urticaria should be evaluated by an allergist-immunologist. A detailed medical and family history and information about your work and home environment, and medications you’re taking are important to review with the doctor. A thorough physical exam looking for signs or symptoms of other systemic diseases is often followed by blood tests, x-rays and/or skin biopsies. Allergy skin testing may provide useful information but usually is not done when the patient is actively suffering with hives.
Hives is one of the most frustrating conditions suffered by patients and treated by physicians. It requires a close relationship between doctor and patient to diagnose any underlying factors that may be causing the condition and to find the right combination of medication that will offer long term relief of symptoms. Thankfully, much research on urticaria is underway. This will hopefully lead to even better treatment options in the future.
Dr. Mona Mangat MD is board certified in allergy/immunology, pediatrics & internal medicine. She graduated from Northeastern Ohio Universities College of Medicine (NEOUCOM) 6 year combined BS/MD program. Dr. Mangat opened Bay Area Allergy & Asthma in 2007. She lives in St. Petersburg with her 4 children & husband.