Lehrer et al. 1994.The authors looked at basidiospore reactivity in US and Europe, as well as the relationship between basidiospore allergy and respiratory disease.  It was found that reactivity was similar overall between US and Europe.  It was also found that a relationship existed between basidiospore reactivity and atopy, asthma, and asthma with rhinitis.  However, a cause and effect relation was not established.