Yes, the antibiotic minocycline can sometimes cause red bumps or rashes on the skin. This is relatively rare, but it can happen. It is usually recommended to stop taking the antibiotic if you experience this side effect. It is not advisable to take Benadryl or any other medication to counteract the itching without consulting a healthcare professional. If the rash is not widespread, the itching is not too bothersome, and you are only taking the antibiotic for a short period of time, you may be able to continue taking it. However, if the symptoms persist or worsen, it is best to speak with a pharmacist or doctor about possibly changing your medication.