Penicillin Allergy

[nicojo]

My son came out in a horrendous rash two days after a course of penicillin. The doc diagnosed an allergy & prescribed an antihistamine. It has now been two weeks since he completed the penicillin course & his rash still flares up once a day - although nothing like the original rash.
Does anyone know if it is normal to take this long for the reaction to work through his system?

[PinkFizz]

Not sure if it applies to children but I developed severe urticaris a long time after a virus and I would come out in this dreadful blotchy rash at some point every day,and not always in the same place.The hospital said it could take up to 2 years to work its way out of my system - thankfully it took only a year,even though I still have the odd day when it re-appears.

[redcrx]

the doctor diagnosed an allergy after the course was finished, was he saying it was an allergy to the penicillin? An alergic reaction usually goes after the first dose of antihistamines unless the allergen is still present in the diet or surroundings

My son has slapped cheek syndrome at the moment and the rash with that can come and go over 4 weeks apparently. Its a blotchy rash that looks like measles and follows 3-4 days of high temp and cold symptoms. Ive read that the rash can flare up a few times and can be made worse when the child is exposed to heat (like a warm bath) or sunshine.

[nicojo]

Thanks fpr replies. Redcrx, yes it was an allergic reaction to the penicillin. I try not to give him the antihistamine unless the rash comes out, as it makes him very drowsy. Like your little one, he can get the same symptoms - cold-like symptoms/temp & his rash gets really bad if he has a bath, even if the water is quite cool.
His reaction does go after the antihistamine, but I assumed it would not return. Can't keep him on the antihistamine all the time!

[redcrx]

I find it hard to understand why the GP couldnt just change the penicillin. And If the rash came out after the course was complete that just doesnt seem right to me, surely if allergic the reaction would occur straight after first dose. Of course you have to believe the GP as they know best.

[spudqueen]

When I found out that I was allergic to penicillin it had all cleared up in a week or two, but it went gradually down not flaring back up. Is it worth going back to the Doctors?

[nicojo]

The reaction was 2 days after he had completed the course of penicillin. Yes, I thought that it would have appeared during the course if that was the allergy.
I have been thinking about taking him back to docs, but it is getting better & I just worry that they will try to get him to take some other form of medication.
Intend to take him to see his homeopath (who cured his colic) just to try & boost his immune system & see how it goes...!

[Hans_Olo]

Allergies only start once the person has been exposed to whatever it is that cause the allergy. But 2 days after it ended does seem a little odd. There can be other reasons for the rash as you dont say what it was or what the penicillin was for, eg tonsillitis + rash may be scarlatina. urticaria may be penicillin but may also be caused by viral/bacterial infections. If it keeps flaring up then I would go back and see your GP as it unlikely to be the penicillin now.

[salmonina]

I came across this thread from a google search I was doing on penicillin allergy as I am currently in a very similar situation to your son. I had tonsillitis a couple of weeks ago, treated by a course of penicillin and then two days after completing the course I came out in a horrendous itchy rash and swellings. The doctor I saw yesterday (rash ongoing for 4 days at that point) stated that it is quite common for an allergy to penicillin (rash - rather than anaphylaxis) to come out a couple of days after finishing the course. I have been advised to keep taking the antihistamines and that the reaction should work its way out of my system. I'd also like to know how long it's going to take - but I guess it's how long is a piece of string?! Jx

[nicojo]

Hi Salmonina. Your situation sounds identical. My son was given the course due to tonsillitis, rash started 2 days after completion of course & basically continued for 3 weeks - gradually improving.
Confirmed with doc that it is quite common to react a couple of days afterwards & he too could not state how long it would take for the reaction to work its way out.
I only gave my son the antihistamine for the first few days, as it wiped him out, then gave him a dose whenever the rash flared up again.
I hope it clears up for you soon, it must feel horrendous. Good luck x

[salmonina]

Thanks nicojo. It's good to hear that someone else has been given the same information and that there is hope of the reaction ending at some point!! Jx