Drug allergies

[Mookie86]

I have a couple of questions about drug allergies.  I am allergic to penicillin and sulfa.

1. I'm wondering if I'm still allergic to sulfa because my reaction was in college, 20 years ago.  I developed hives and a rash when I had a sulfa antibiotic for a sinus infection.  Is there a way to test if I'm still allergic?  I'd rather not go through trial-and-error when I'm sick.  I developed the penicillin allergy about five years ago, and I had hives and itchiness for 5 days even with 50 mg of Benadryl every four hours, so I'm not questioning that allergy.

2.  I've heard of drug desensitization.  Given how few antibiotics I can take with being allergic to both sulfa and penicillin, I may want to consider it.  Is it an option for sulfa?  That reaction was less extreme than the penicillin one, so I would think that's a better candidate for desensitization.

[CMdeux]

Yes, with skin testing, and yes I think so.


Even penicillin allergy isn't as persistent as was once believed-- it'd TOTALLY be worth it to get tested.



(I just happen to know the answer to this one because I've totally creeped on our allergist, who is something of a guru in this particular sub-niche--but I've only creeped on the guy professionally, honest!!  If I run into them around town, I totally ignore them and leave him and his family alone.      )

You'd have to ask someone like that whether it's worth it to desensitize using a slow protocol, or if they'd do it inpatient as a rush-protocol assuming that you ever needed one or the other.

[YouKnowWho]

I know they do antibiotic dsx - do they do it for pain killers like ibuprofen?

(Sorry to derail, just curious because it would make my life easier).

[maeve]

I have been allergic to penicillin since I was a baby and just last year developed an allergy to sulfa drugs when I had a reaction to Bactrim. I'd developed an allergy to cephalosporins a few years earlier (though I had to argue with the urgent care doctor who prescribed it because she didn't acknowledge GI problems as a symptom of an allergy--this was within 15 minutes of the first dose so it was not a case of the antibiotic killing the gut flora; however, my GP believed me).  I also developed an allergy to doxycycline a few years ago as well.

[Mookie86]

I got prescribed Doxycycline today for a sinus infection and bronchitis.  That's what got me thinking about my drug allergies.

Maeve, what's in Doxycycline to which you're allergic?

[notashrimpwimp]

Does the desensitization hold? I was recently diagnosed with an anaphylactic reaction to penicillin, and wondered if this might be a possibility for me as well.

[rebekahc]

I've always been allergic to penicillin and had an anaphylactic reaction to cephalosporin about 10 years ago. The allergist told me about 10% of penicillin allergic people will also be allergic to the cephalosporins and almost all cephalosporin allergic people will also be allergic to penicillin.

DS has reacted to duricef, omnicef (both cephalosporins, so we also avoid PCN with him) and Cleocin (which is a different class of abx).  Years ago, his allergist told us she could do rapid desensitization when and if it was necessary he take one of the classes of abx to which he's allergic. She didn't feel there was any reason to desensitize until needed. If I remember correctly, part of her reasoning was that the desensitization didn't always last, so why waste the effort before it was needed.

DS has had anaphylaxis to ibuprofen and acetaminophen made his eyes swell shut. Thankfully a few years ago we were able to do an in office challenge and found out he outgrew the acetaminophen allergy.  It was really hard when he was allergic to both because all the narcotic pain relievers they were able to offer him after surgery when he was little were mixed with one or the other. The doctor didn't have the right forms to prescribe the 'controlled' straight narcotics and finally resorted to giving us phenergan so he could sleep through the pain.  Our allergist never mentioned desensitization as an option for the pain med allergies, but I think she would have if she thought it possible.

[CMdeux]

Right-- and the other reason not to do it until you need to is that you never really know in advance WHICH abx is going to be needed.

[GoingNuts]

Yes, with skin testing, and yes I think so.


Even penicillin allergy isn't as persistent as was once believed-- it'd TOTALLY be worth it to get tested.



(I just happen to know the answer to this one because I've totally creeped on our allergist, who is something of a guru in this particular sub-niche--but I've only creeped on the guy professionally, honest!!  If I run into them around town, I totally ignore them and leave him and his family alone.      )

You'd have to ask someone like that whether it's worth it to desensitize using a slow protocol, or if they'd do it inpatient as a rush-protocol assuming that you ever needed one or the other.

Yes on the above.  DS appears to have outgrown his penicillin allergy (knock wood, poo-poo-poo) but it is still not recommended that he receive it via IV.  And yes, they discussed desensitization if he hadn't outgrown it.  We don't know if he's outgrown his cephalosporin allergy.

[Macabre]

My allergist talked with me about rapid desens for penicillin last month (not about doing it to me but about it).  She said it usually goes away after the round of penicillin--and the desens has to be done in a hospital, in-patient.  It has its uses but is not the kind of desens we think of around here.


There has been a LOT presented in the last three years at professional conferences about testing/challenges for penicillin outgrowth. I have seen a lot of live tweeting during sessions about it.  I'm allergic to penicillin, and my ears have pricked up when I've seen tweets.

[Mookie86]

I read online that there are 2 forms of desensitization for drug allergies. 1 is rapid, which needs to be inpatient. It sounds like you do it only if you need a medication to which you are allergic and there are no alternatives. The other form is gradual. That's the one that might be an option. However, if results don't stick,  there is no reason to do it.

Does gradual desensitization tend to last? I haven't looked if studies saying drug desensitization doesn't last were looking at rapid or gradual desensitization.

[CMdeux]

I'm guessing that the risk-benefit wouldn't make it worth it.  That is, it's a one-time, rare event to NEED the ABX, and desensitization is something that you do at the physician's office pretty regularly-- think allergy shots.

Going into SCIT, you sign a bunch of scary waivers that indicate that you understand that anaphylaxis is a possibility, and that the results are far from guaranteed-- either during or after.

That said, it doesn't add up to do slow desens. for abx unless you have a really compelling reason why you NEED to regularly be taking them.  I suppose if you planned major surgical procedures for a particular year, or something like that, then maybe.

[Macabre]

Well, if you get secondary bronchitis that likes to flirt with the notion of becoming pneumonia frequently like I do, it's really good to have options. It's why I brought up having a challenge for penicillin.

I get bronchitis once a year, sometimes two. It's the rare occasion that I get get through it without abx (I did this last fall, buy typically no). I Have been allergic to penicillin since a baby--but not sure I still am. I refuse to do Quinolones. I'm guessing it's not a true allergy, but they make me so sick. I do not enjoy cephalosporins but can take them. I can do doxycycline (and my face loves it) but it does cause bad acid reflux for me--or at least bad acid. And doxycycline is associated with DS' accident. It's why I feel I. Part responsible (though I don't best myself up anymore).  I don't want to talk about it--just to say that there is a very emotional component to taking doxycycline.  And in the past it hasn't been effective against bronchitis anyway.

My go-to is a Z-pack, but it's obviously not an option to use it all the time.

I do need options. It woykd be great if I weren't allergic to penicillin.


So if there is an effective slow desens, I'd love to know about it. However, since my allergist who does slow desense of food and environmentals through OIT which I do at home didn't mention OIT as an option, I'm guessing the desens can't happen through OIT.  And as cm suggested, in guessing it's an in-office thing.

There's no realistic way that could happen for me in the next couple of years. I could not manage allergy shots for myself while working and taking time for managing kid things.  But maybe once DS goes off to school I would have time for that. It would be cool.

However, in my case, I want to see if I'm still allergic. My allergist has ordered penicillin for my July ImmunoCAP. Yea!

[Mookie86]

Ooooh you can do a blood test for drug allergies? Then maybe I should do the blood test, and if it is negative, then do a skin test.

There are very few antibiotics I can take with penicillin and sulfa allergies, and the remaining options have worse side effects. It would be really good to have more options. Also, when I had shingles, there was no non-Sulfa alternative to something that would have helped.

[Macabre]

I had forgotten about Cleocin. I used to take that for bronchitis as a kid.