Swelling at the site of bcg vaccination.

Immediately after the BCG vaccine there is a small swelling at the injection site which persists for 6-8 hours. After that the swelling disappears & the injection site looks normal. After 6-8 weeks a swelling reappears which looks like a mosquito bite. It grows in size & forms a nodule which breaks open & discharges some fluid & forms an ulcer. The ulcer heals by forming a scar. The whole process takes 2-5 weeks. Some times this process of ulceration & healing recurs 2-3 times. Ultimately the typical puckered scar is formed which remains for lifetime.  Injection site should not be pressed or rubbed. It should not be fomented. Nothing needs to be applied locally. Infact, bath with soap and water should suffice even when it has ulcerated.