OCCASIONAL OCCURRENCE of a flare-up at the site of a previous smallpox vaccination scar is not as well known as it should be. Sommerfeld and Ehrengut1 reported five cases of this phenomenon. One case of reactivation of a smallpox vaccination scar was recently seen, and, when other patients were queried about this type of reaction, another quickly came to light.
Report of Cases
A 56-year-old woman had had a smallpox vaccination as a child and gave a history of local reactions to insect bites. She was revaccinated on her left arm and developed a primary reaction. Seven and one-half months later she was bitten by insects on her right leg and left heel. These areas swelled, became red, and itched severely. Two days later she noted itching and redness over her recent smallpox vaccination scar and saw that ten vesicles had appeared at the vaccination site. Material
Diamond MT, Joffe B. Reaction at Old Vaccination Site. JAMA. 1965;194(12):1325-1326. doi:10.1001/jama.1965.03090250059024