Wednesday, April 10, 2013
Breaking Out in Hives?
Hives- the very thought of these itchy, raised, red splotches make me start to squirm and scratch. With our oak allergy season in full bloom here in Austin, we see the full spectrum of allergic complaints- from sneezing, sore throats, dry coughs and itchy eyes to skin reactions such as hives. The medical term for hives is "urticaria". These lesions come and go, and often cause a burning sensation along with the itch.
In the previous blog entry about allergic eye problems, I mentioned that histamine (the substance that causes the redness and itch of allergic reactions) is stored in cellular level containers called mast cells. With urticaria, the basic problem is that these mast cells degranulate, releasing their highly inflammatory contents. The good news is that typical lesions resolve within 24-48 hours, but the bad news is that they can quickly reoccur and become a chronic problem.
But Doctor, what caused my hives? Was it the shrimp I ate yesterday?
Unfortunately, identifying the triggering cause for hives can be extremely challenging, because there are so many different potential culprits. Infections (especially from Strep and mononucleosis), drugs, foods, pollens, chemicals, metabolic disorders (like thyroid) and even rarely underlying cancers can all be to blame. Additionally, urticaria can be triggered physically, from cold or heat, pressure, or sunlight.
Treatment focuses on antihistamines initially, and often this is all you will need- especially if this is the first time you have ever had hives. Non-sedating antihistamines are used for daytime, and our old standby diphenhydramine (Benadryl) works well at night for those who need help sleeping. If these medications are not enough, clinicians have stronger medications such as steroids or other histamine receptor blockers that may be added.
What can you do as well? Avoid extreme or sudden changes in temperature, including hot showers. Avoid alcohol and NSAIDS (ibuprofen, naproxen), both of which can aggravate hives. Stay out of the sun. Applying topical calamine lotion provides relief to some people. If you develop a chronic problem, consider keeping a diary to help identify potential triggers. Happily, approximately 70% of people with first time hives will have resolution of their symptoms within three days, regardless of which treatment they use.
BOTTOM LINE: If you break out in hives, start with OTC antihistamines and be assured that it is okay to give yourself a couple days before you head to your doctor, as long as your itching is tolerable.