Why BCG vaccine cause blister?

Normal Reaction. It is normal reaction to the vaccine.You get bluish red papule which may look like a blister 2to3 weeks after the vaccination.After about 6 weeks the pustule ulcerates forming a lesion approx. 5 mm in diamneter. Scab forms and heals usually withn 3 months after vaccination and results in a permanent scar at the puncture site.
Body reacts with it. The bcg is not used in the U.S. But is used in many countries. Our immune cells react with the substance. The U.K. Website says: two to six weeks after the injection, a small spot may appear at the site of the injection. It can grow into a circle up to 7mm in diameter and may become crusty where fluid has dried on the surface. It can be painful and bruised for a few days, but will eventually heal.

Related Questions

Aftr BCG vaccine, why appearance of blister is normal? Is it caused by BCG antigen?

BCG. Bcg is an intradermal injection at the deltoid. If bcg is accidentally given subcutaneously, then a local abscess may form that can ulcerate, and may require treatment with antibiotics. Without treatment it could spread, causing damage to other areas. If pus is aspirated and analysed and treated correctly, the abscess will generally heal on its own in a matter of weeks. Read more...

Why aftr 2 month injection of BCG vaccine, the baby had blister on the left upper arm? Why it took 2 month?

BCG. Bcg is an intradermal injection at the deltoid. If bcg is accidentally given subcutaneously, then a local abscess may form that can ulcerate, and may need therapy with antibiotics. Without treatment it can spread, causing damage to other areas. If pus is aspirated and analysed and treated correctly, the abscess will generally heal on its own in a matter of weeks. It may take time to develop. Read more...
Blister after BCG. Thanks for your question. The bcg vaccine contains some preservatives. Sometimes, people can have irritation in their arm from the preservative, and this can be delayed even several months from the vaccine. It's not a dangerous reaction, but i recommend that you take the baby to your primary care physician to have the arm looked at. Read more...

Bcg vaccine caused no sign of red dot or swelling. So is that normal?

Bcg vaacine. If your question is that you have had BCG vaccine and your PPD test did not show any red dot or swelling, that means you do not need any further testing, you do not have any evidence of tb. Read more...