not allergic to penicillin

[redbird]

I saw the allergist this morning. He asked me a bunch of questions, including wanting me to describe the rash and about medications other than the antibiotics I was wondering about, and decided it did make sense to test for an allergy to penicillin.

So he took the residents* off into another room, where he either showed them diluting the penicillin or had one of them do it. Then I got pricked (they say "scratched") five times, and sent to wait for 20 minutes with my book. No reaction to anything except the histamine control. This is good, this what we want.

To confirm, he then gave me 2 amoxicillin capsules, totaling 500 mg, and had me sit in the waiting room a while longer. I had no obvious reaction, and he also looked at the areas where I had broken out last winter, i.e., chest, neck, and calves.

So I am not allergic to penicillin or amoxicillin, and can safely be given that family of antibiotics. However, as my GP warned me, there is no test for Bactrim allergy. There is also no test for a cephalosporin allergy as such. So:

I am to avoid Bactrim. If possible, avoid cephalosporins, and if a doctor thinks I need one, contact the allergist. Ditto for sulfa drugs other than Bactrim. In either case, he would probably want me to come in, and take the first dose in his office just in case. Sulfanilamides are a large family, including a number of things other than antibiotics, and some of those are more likely to cross-react than others. (One of the residents mentioned Lasix as one that would probably be okay, if I ever need it.) Taking the first dose in his office would be a precaution against anaphylactic shock, the thing allergists worry about most. It wouldn't do anything for the rash a month after taking the drug, or even a week into a ten-day course of medication.

The above is more or less what I was hoping for: the best outcome given the previous reactions and the current state of medical testing. I also verified that tetracycline is not a sulfa drug, so I can still use that. Just curious.

*I assume they were residents, because they were fairly young, and his office is in a teaching hospital. Not med students, because he introduced each of them as Dr. $name, not Ms. $name.

Comments

[sraun]

My wife is allergic to morphine, at the anaphylactic shock level. She first found out while lying in a hospital bed - probably very close to the best possible time. (Kind of like having a heart attack in the middle of a stress test - I know someone that happened to.)

[redbird]

Yes, if it has to happen, that's the place. (With the stress test, if they aren't expecting patients to have a heart attack, they're likely to be prepared for it, as well as for discovering that there is nothing wrong with the patient's heart.)

[flick]

Why can't they test for Bactrim? Wouldn't it just be the same process with a scratch test? Am intrigued!

[redbird]

I don't know. Both the allergist and my GP said that they can't test for Bactrim/sulfa drug allergy. The allergist added that they can't test for cephalosporin (such as Keflex) either. I may have to ask google why.

[flick]

How peculiar!

[pantryslut.livejournal.com]

I'd missed that you had a Bactrim reaction. I'm just here to say I sympathize, and recount this story from when I informed my doctor that I have a sulfa allergy, too:

She asked, "what are your symptoms?"

I replied, "104-degree fever, headache, severe fatigue and hives."

She kind of blinked and said, "well, we won't be giving you any, then."

[redbird]

Oh, dear.

My regular doctor is the one who diagnosed the sulfa allergy, based on a painful/itchy red rash on my chest and neck. I was startled, because it developed weeks after I'd finished taking the Bactrim. So she won't be giving me any, though I may have to remind future/other doctors.

[pantryslut.livejournal.com]

Interesting. Mine too took a long time to develop and that hampered diagnosis. Sulfa drugs are weird.

[mjlayman.livejournal.com]

I was given some and turned purple. I spent the day in Urgent Care being watched. Now I have Sulfas in the allergic section on the sheet that's folded in my wallet and batches of other places.

[malibrarian.livejournal.com]

Glad to hear that you're not allergic to penicillin or amoxicillin. I think that they're much more useful drugs. I've lived for almost 25 years without sulfa drugs after I was covered with hives from my forehead to my knees in a mere 45 minutes (this was after I went to the doctor's office with 10 of the first 15 symptoms of an allergic reaction to bactrim, which he totally missed.) Spent 3 days in the hospital getting it washed out of my system.

[yarram.livejournal.com]

Not being allergic to -cillins is a useful thing. I discovered through empirical testing that I am not allergic to Cephalosporins, which was useful when they gave me something in that family post-appendectomy. (It also gives my doctors something new to throw at my ear infections. Yay for classes of medications my bugs haven't met yet!)

I am amazed that despite my numerous pollen/dander allergies, I have yet to discover any confirmed food or drug allergies. I suppose I should be grateful for immunological selectivity, but tree bukkake season makes that difficult... ;-)

[amaebi.livejournal.com]

Oh my, oh my, I can see that it's as good as can be, and yet....

[dichroic.livejournal.com]

I should probably save this post. I have a minor allergy to sulfa drugs (as in, I got mildly itchy once and they said, "Well, once you have an allergy it can get worse so from now on tell your doctors you're allergic". But the other day I was trying to explain the allergy to a new dentist, she didn't recognize the term 'sulfa drugs', and neither of us had any idea what that might be in Dutch. So now I can look back at this post for other associated names.

[athenais.livejournal.com]

Well, it's always good to know for sure what one is allergic to. I say I have an allergy to amoxicillin, but really I don't, my stomach can't tolerate it. Penicillen is fine.