Hello,
You seem to be having sulfa drug allergy.It occur when your immune system recognizes a drug as a foreign substance and tries to protect you from it.
Take some over the counter antihistaminic like benadryl or Claritin(loratidine). Sometimes double conventional doses of these non-sedating antihistamines such as Cetirizine(zyrtec), Loratadine(Claritin) and Fexofenadine may be needed to get symptom relief.Apply mild corticosteroid cream like dermacort on the rash.It should help.
If the symptoms still persist then pls contact your doctor as oral steroids may be needed.If you have any respiratory difficulty,palpitation or wheezing along with,then pls contact ER immediately.It could be anaphylaxis.
Take care and pls do keep us posted on how you are doing.
I posted this in two forums and am not getting an answer. Should I pm a doctor?