Its not a disease, its an acute inflamation of the patella tendon where it inserts into a groove at the top of the tibia.
The key part of the recovery process is activity modification. That means avoid running on hard surfaces and if your playing sports that are aggrivating it, you may have to scale back your intensity or training.
Pain inhibitors will help you deal with the pain, but be aware that if you continue irritate the tendon insertion, it will lengthen the period of recovery.
That said, most non steroidal anti inflamatory drugs (you can get over the counter or prescribed) will help take the edge off the pain
On the plus side, it is a process which will resolve as you get older, no matter how you treat it.
The bad news, if your skiing really makes it hurt, you might have to take it easy for a season.
Or not.
Best of luck bro.