My oldest kid recently finished up a 10 day amoxicillin prescription, on the 9th or 10th day he started breaking out in hives which got worse for about a week (with swelling and other symptoms). Having some little experience with allergies we took him to the doctor asap and got prednisone and an antihistamine, so I’m not asking for medical advice.
Question number one – how long does an antibiotic like amoxicillin stay in your system? Watching the progression of the symptoms, I suspect it’s several days after you stop taking it, but up until this point I assumed that the body would flush stuff out fairly quick.
Pregunta número dos – Is there a test for this allergy? The doc said that he wasn’t sure the reaction was to the amoxicillin - the guy’s not an allergist and he has no idea what the boy might have gotten into since he was seen last (last seen?), but I’d really like to know before next time he needs an antibiotic.
This is only anecdotal, but I had a similar reaction to amoxicillin when I was… 15? I went back to my doctor, and she and said that since I’d had an allergic reaction to it, she was going to assume that I had become allergic to all penicillins – she got me off that drug right quick.
I don’t know if there’s a test for it, but since allergic reactions tend to get worse each time you are exposed to the allergen, I haven’t felt the need to experiment with it – I haven’t had any penicillins since then, and I used to wear a medic-alert bracelet with that info on it. I have since decided that that was overkill, and I just make sure that people I spend lots of time with know that I’m allergic to it in case there is ever some random emergency where someone might try to give me some.
Hives is one of the most common skin rashes that people present to the ER with. In something like 70% of cases the exact cause is never deterimined. The exposure to amoxicillin may be a coincidence or it maybe the cause. It happens sometimes that people develop allergy symptoms after repeated exposure, not just the first one. An allergy specialist should be able to test for an amox allergy, not sure what that costs
I had amoxicilin for a mouth injury a couple months ago (I am 29). I never had problems with this drug previously. Around day 8 (out of a 10-day prescription) I started getting a rash with small blisters on the back of my hands, which eventually spread to the inside of my arms, the palm of my hands, and both of my feet, but nowhere else. I tried narrowing it down to possible poison ivy, which seemed unlikely when it started spreading. I eventually figured it might be the drug, but since I had only one day left on the prescription, I just finished taking it, and the problem cleared up within another day or two.
I guess the next time they ask for drug allergies I’ll mention what happened, and go from there.
Identical experience here to those previously described happened to me a few years ago. In my 50s. “But I’m not allergic to penicillin!” I proclaimed to my doctor. “You are now,” he responded. He also cautioned that although this was only a set of itchy hives this time, it could be worse after subsequent exposures and that, since there are lots of other antibiotics that can be used instead, I should simply avoid penicillin from then on. To answer the first question, it takes a matter of days for the stuff to be completely gone, from what my MD told me.