Can BCG jab reaction take so long to appear?

[OopsyDaisy]

My LO had her BCG jab done 5 weeks ago but it's only now that a red bump has appeared at the site of administration. Has anyone else's babies had reactions that took this long to appear? And do you know if this bump will go down with time?

 

[Melanie]

Thea had her BCG at 1 day old and she was exactly 6 weeks when it the mark appeared. The mark became a weepy hole when healed up in about three days. She is over a year now and the BCG is a very noticeable lump on her arm.