What Causes Severe Acne While Being Diagnosed With Costochondritis?

my son aged 17 has severe acne for a couple of years. He is generally lethargic and unwell and has had severe epigastric pain on and off for 18 months and has recently been diagnosed as having costrochondritus. He has been prescribed Ibuprofen and Ranitidine which is ineffective. a)Is there a link betweek acne and costrochondritus and b)what tests should he have to check that it is not pancreatitis.