ASK THE DOCTOR: Allergic rashes aren't uncommon
By DR. JIM MITTERANDO
The Patriot Ledger

Q. My skin sometimes breaks out in an itchy rash for no known reason. What could be going on?

A. Allergic rashes affect almost everyone at some time. Rashes can develop from a certain food, medicine, soap, cream, cosmetic, detergent, or even dye from clothing.

If you develop an itchy rash, there is a good chance it is an allergic rash. Other causes of itchy rashes can include eczema, which is associated with dry skin and mostly appears in winter, and poison ivy, which is a different kind of allergic rash that often blisters and is extremely itchy.

For the generic, red-dotted, itchy rash or for those big hives, the best medicine is Benadryl taken orally.

Please note that Benadryl can be sedating. Any antihistamine, though, will help with a rash, from Chlortrimeton and Tavist to the non-sedating prescription antihistamines Allegra, Claritin and Zyrtec.

Calamine lotion (that pink stuff) is not very useful and just makes a mess. I also do not recommend Caladryl, which can cause allergic reactions and does nothing to get rid of the rash. (It just briefly takes the sting out of the rash).
We human beings have a tendency to rub creams or balms on our skin when it is itchy or rash-ridden. But often, the best thing to do is to take your antihistamine pill and not to touch your skin.

Scratching often releases more antihistamine and makes the rash itchier and redder.

If you feel you must apply something, use a simple moisturizing cream that you have tried before and know you are not allergic to. Useful moisturizing creams include Moisturel, Lubriderm, Cetaphil, Eucerin and Neutrogena.

People commonly think expensive is better, but this is not true. Lubriderm and Moisturel are inexpensive and effective.

Hydrocortisone and other steroid creams often do not help with a systemic allergy. These creams are more useful if you touched something that you are allergic to, such as poison ivy, and have a localized reaction. Even poison ivy often requires a strong prescription steroid cream and may not be relieved with over-the-counter hydrocortisone.

Lastly, do not bathe the area frequently or apply wet soaks to an itchy rash, which will often dry the skin and make it even itchier. The one exception to this rule is poison ivy, which is often weeping and oozing. In this case, frequent applications of a wet washcloth may help speed the drying-out of these wet blisters.

After you have treated the rash, you can play detective to find out the culprit that caused it. Often, rashes come and go, we never know their causes and, thankfully, they often do not return. If, on the other hand, the rash keeps coming back, follow up with your doctor for further evaluation.

Dr. Jim Mitterando is a family doctor at Health Care South/Cohasset Family Practice and a staff member at South Shore Hospital in Weymouth.

Readers should send questions to: Ask the Doctor, The Patriot Ledger, P.O. Box 699159, Quincy, MA 02269-9159, or by E-mail to his attention at features@ledger.com.

Questions of general interest will be answered in this column. The information in this column is not intended to diagnose individual conditions, and individual replies are not possible. Readers should see their own doctors about specific problems.

Copyright The Patriot Ledger
Transmitted December 26, 2000