URGENT! A bump on my platy's head

[aerofish]

A red-wag platy i got a couple weeks ago had this light brownish bump on the top of his head. I didn't think much about it until today. The bump is now on the right side of his head (just behind the eye). There is no more a bump on the top!

what is this??? and what should I do? Will it spread??? Will it infect my other fish?

 

[amazingbioloboydp]

try posting this in emergency.Im not great with this stuff.but i know u will get more hits there.