How long can a drug rash last after you stop taking the medication?

And if the rash is getting worse, you will need to see the ER. Please tell us which medication so we can help you further.

Should you develop troubles swallowing, breathing or your tongue swells you need an ambulance immediately.

Just so you know.

Pledge is right. It would also depend on whether it was an immediate allergic reaction or one that developed over time. It should probably fade fairly quickly if it was a first time use reaction. If it developed over time, it will take longer to fade as you have a build up of that medication in your system and you will likely continue to suffer some kind of rash until the medication is completely out of your system. Please remember that if your taking benadryl or it's equivalent orally, you should not use the benadryl cream on your rash as that will overload your system with antihistimine. Use an anti-itch cream that doesn't contain an antihistimine. Best of luck to you!
Lisa

Hello jaysoncat. It will depend upon the drug/medication you are taking, meaning the name and the condition and as to why. Regards pledge