My 6 years old kid has molluscum , the dr. first treated it with nitrogen. it spread more , now dr. suggested an immunity injection?

Molluscum: Generally, molluscum contagiousum is self-limiting and goes away on its own. The usual time period is 6-18 months if you do nothing at all. Whenever they are treated, they actually may spread more, so leaving them alone is a reasonable choice in children with a normal immune system (the question is different in people with compromised immunity). Avoid scratching and keep them clean.