Passage: Michel Pistor (1924–2003) performed clinical research and founded the field of mesotherapy.  Multi-national research in intradermal therapy culminated with Pistor's work from 1948 to 1952 in human mesotherapy treatments.  The French press coined the term Mesotherapy in 1958.  The French Académie Nationale de Médecine recognized Mesotherapy as a Specialty of Medicine in 1987.  The French society of Mesotherapy recognizes its use as treatment for various conditions but makes no mention of its use in plastic surgery.   Popular throughout European countries and South America, mesotherapy is practiced by approximately 18,000 physicians worldwide.

Question: What general area of medicine is Pistor associated with founding?
mesotherapy