How can I get a clear acne-free skin in a week?

Find an old bottle.. ...On the beach, rub it, and hope a genie comes out. In all seriousness, we are doctors, not magicians. A strong oral steroid like Prednisone can be used to temporarily clear your skin in a short period of time, but steroids are powerful drugs and should not be taken for cosmetic reasons unless absolutely necessary. A much wiser plan is to plan further ahead and get on a sensible longterm regimen.
Clear acne. The quickest way to control acne for a short period of time is to take Prednisone 5 days before the event. This is not a permanent way to control acne. You take Prednisone 10mg three times a day for 5 days as long as it is not contraindicated. This treatment is used for proms or special events but after the event the acne may flare.