More on MSG and Allergic Reactions

Q:  I was disappointed with your response to a letter from the person allergic to MSG (or something else) who experienced a choking sensation after eating certain foods. Food allergies are potentially more dangerous than your response implied. Attacks can worsen with repeated incidents and/or vary based on the amount of allergen ingested. That person should definitely (not just probably, as you advised) speak to a doctor who is knowledgeable about food allergies so he or she find out specifically what makes them sick, what foods to avoid and what to do if a serious attack occurs. Serious attacks can cause the throat to swell enough so the person will not be able to breathe at all. If you can't breathe, waiting 15 minutes for the attack to pass isn't an option.

It's important that people understand food allergies can kill. It's not hay fever; it's more like a bee sting. I sometimes think people are too dismissive when I tell people my son can't have anything containing milk products. When visiting restaurants or people's houses, it's hard to make people understand that just a little taste could possibly kill him. And when people in your position don't address these issues as serious health problems, it makes my job in keeping my child safe a little harder. Please keep this in mind next time someone writes in about a food allergy.

A:  I certainly hope I didn't imply that food allergies should NOT be taken seriously. Quite the contrary -- that's why I've printed your letter in its entirety. It must be very frightening to be away from home and come down with an attack!

There are different types of allergic reactions -- some immediate (within minutes) that could result in someone having a life-threatening respiratory arrest (e.g. bee sting), and some delayed (taking hours or days), like a skin rash. Penicillin allergy is one that can be of either type.

A patient just called me this morning because of an itchy skin rash that developed five days after taking amoxicillin. Although MSG has been shown to cause asthma in some people 12-14 hours after ingestion, it does not appear to be an "immediate" type allergic reaction.

"Dear Doctor" is a compilation of patient questions answered by doctors from the Medical College of Wisconsin.