I'm 17 and I've had p for about 8 years now. I was just wondering, how serious a case of P do you need to be put on a pill treatment?
Because the topical steroids and such that I'm on aren't helping anymore.

I responded to you on the general forum, which is probably the best place for you to post because it is the most viewed and most active. Regarding pills, I would say that it's not so much the severity as much as it is the next step after topicals either stop working or have thinned the skin.
10% coverage or more is clinically severe...keeping in mind that the palm of your hand is equal to 1%, but that does not mean that you have to be 10% covered to start using oral or injectable medications to treat your P. A good derm will consider the way a person's P has affected their emotional and social well being when deciding how aggressive to treat the P.
Before jumping at pills though, you may want to look into UVB or PUVA treatments. I even looked into biologics before oral treatments (I use one of the injectable biologics now). Hopefully you derm is knowledgable about P and it's treatments!