Question
My baby has received the BCG vaccine more than a month ago, but the swelling on the arm where it was injected has not yet subsided. When can it return to normal?
Answer
Three to four weeks after receiving the BCG vaccine, a bean-sized lump usually appears at the injection site, which is red or purple in color and may have a small bump in the center, gradually breaking open and secreting fluid. About two to three weeks later, the broken area will form a scab and fall off, leaving a small scar. Your baby can bathe and be fed normally. If the scab does not form within three to four weeks or if a lump appears under the armpit, you should take your baby to the hospital for a check-up.