"Bernardino Ramazzini (1633-1714 AD), known to some as the father of sports medicine, detected a link between asthma and organic dust. He also recognized exercise-induced asthma.

"At the beginning of the 20th century asthma was seen as a psychosomatic disease - an approach that probably undermined any medical breakthroughs at the time. During the 1930s to 1950s, asthma was known as one of the holy seven psychosomatic illnesses.

"Asthma was described as psychological, with treatment often involving, as its primary component, psychoanalysis and other 'talking cures'. A child's wheeze was seen as a suppressed cry for his or her mother. Psychoanalysts thought that patients with asthma should be treated for depression. This psychiatric theory was eventually refuted and asthma became known as a physical condition.

"Asthma, as an inflammatory disease, was not really recognized until the 1960s when anti-inflammatory medications started being used."


from http://www.medicalnewstoday.com/info/asthma/asthma-history.php

Presumaby the idea about asthma being unknown before the 60s is implied in the last sentence of the quote.

The beginning of the articles says asthma was known in Ancient Egypt and before even then.