HIVES/URTICARIA

Hives (aka urticaria) is a common, itchy, allergic condition of the skin. In about 10% of the cases, a recent illness (usually viral), a new medication or food is the trigger. Usually, you know that. "I just started that new medication and now I have a rash", or "Every time I eat cantaloupe, I break out in a rash", or "My child got a cold and now has hives". But most of the time, the cause is what we call either idiopathic (we don't know why you have hives) or "autoimmune" where your own body is attacking itself, for no good reason.

When will the hives go away?

Most cases (about 75-90%) of new-onset hives goes away within 6 weeks. If your hives becomes chronic (lasting more than 6 weeks) you have a 50:50 chance of it going away within a year.

Is there anything I should make sure to tell the doctor?

• Make sure to tell your doctor if you get short of breath with the hives or if there is any swelling of the face, neck or tongue.
• Rarely hives may be triggered by heat, cold, pressure, etc. These are called the physical urticarias. Make sure to tell your doctor if you know or suspect that something is triggering the hives. See the questions below.

What questions to ask yourself if you have new onset hives?

• Have you had a cold or otherwise been sick recently?
• Did you start any new medication, vitamin, supplement or any pill recently?
• Have you recently traveled outside of the country (refers to risk of parasitic infection)?
• Can you think of anything that might have brought on the hives?
• Are any parts of your body swollen, e.g., lips, eyes, tongue?
• Do you have any dental problems that need attention?
• Are you experiencing any of the following with the hives: nausea, diarrhea, abdominal pain wheezing, difficulty breathing, joint pain or swelling, headache?
• Do any of the following seem to cause the hives: aspirin, certain foods (e.g. red meat) alcohol, any medications. (Usually hives appear within minutes to an hour or so after eating a triggering food. Red meat is the exception which can cause hives 4-8 hours after eating.)
• Do any of the following seem to cause the hives: pressure, sunlight, rubbing, scratching, exercise, heat, cold, vibration, water.
• Do you have any of the following medical conditions? thyroid disease, rheumatoid arthritis, celiac disease, or type 1 diabetes.

Let your doctor know if the answer to any of the above is yes.

Should I keep a diary?

Some patients have kept a diary of when the hives occur including:

• the date and time the hives appear
• what you were doing just before they developed
• what you have had to eat or drink

If any common factors emerge when the hives occur, you can try to temporarily avoid these to see if it helps. Let you doctor know of anything you find.

Can't the doctor just order blood work to figure out the cause?

Unfotunately, the chance of finding anything relevant with blood work is low, especially for acute urticaria. For chronic, your doctor may get some screening blood work. If there is recent travel to a tropical country, stool sample for ova and parasites may be ordered. Usually these tests are normal however.

Treatment

What to avoid

Aspirin and non-steroidal anti-inflammatory drugs e.g., Alleve (naproxen), Advil (ibuprofen), can worsen urticaria so you may want to avoid these. Tylenol (acetaminophen) is okay.

Antihistamines for Adults

Over-the-counter antihistamines are the mainstay of therapy. They should be taken daily to prevent the hives. The goal is the complete elimination of the itch. So-called second-generation antihistamines are best (least-sedating) and are listed below. The starting dose is one pill a day.

• Allegra (fexofenadine) 180 mg (not the 60 mg tablet)
• Zyrtec (cetirizine) 10 mg
• Claritin (loratadine) 10 mg

Pick any of the above and start with one pill a day for three days. If the rash is suppressed, great. Continue taking one pill a day. If not, speak with your doctor to see if it is safe to go higher. The main risk is sedation--being too tired to work, drive etc., but this is uncommon. Your doctor may say, add in a second pill, e.g., one pill morning and night. Do that for three days. Again, if the hives are not controlled, add in another pill etc. until you get to two pills twice a day. In the majority of cases, this approach is successful in suppressing the hives and/or itch. If not, let your doctor know. Again, the main side effect of the above approach is drowsiness. Allegra is preferred as it is--for most people--the least sedating. But make sure you get the larger 180 mg tablet (not the 60 mg).

First generation antihistamines like Benadryl (diphenhydramine) are okay, but they are much more sedating, so best to avoid, unless taking at night.

If the above fails and no cause of the hives can be found, then Xolair (omalizumab) as given by an allergist may be recommended.

Antihistamines for Children

Check with your pediatrician.