Hello. Welcome to ask the doctor.
I understand your concern.
It seems that you have developed infection of the scar as a result of scratching. You got vaccinated long back so it is not related to the small.pox vaccination. It is simply infection of the scar like any other scar.
You can apply mupirocin 2 percent over the affected area. If severe, oral antibiotics are also given like cloxacillin.
Visit your doctor so that he can examine you and give you prescription accordingly.
You can share my opinion with him.
I hope it helps.
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.