If cocaine comes in contact with your skin will you fail a drug test?

It depends upon the type of test you are referring to. If a sample test of the powder on your skin is taken, yes, the test will show positive for cocaine. If you are speaking of a blood, or urine test, no, because the powdered cocaine would not have crossed the barrier to be contained within your body systems. HOWEVER: If there were sufficient powder on your skin for you to have inhaled it (thru mouth or nose) then it could show up in tests also.