PPD - Purified Protien Derivative. A skin test for tuberculosis antibodies. A false positive can occur if the patient has been exposed to TB in the past but does not have active TB . Also called Mantoux Test.
I had to look up the proper spelling of Mantoux. Damn Frenchmen.
Is there a medical word you would like to know the definition of? Leave a comment and try to stump me. I promise I'll try to define it without references and I'll let you know if I couldn't do it.