Treatment of hay fever with alum precipitated pyridine (Allpyral) ragweed pollen extracts--a clinical reappraisal.

This report reviews the results of prophylactic immunotherapy carried out on 105 ragweed hay fever patients treated for at least two years with an alum-precipitated pyridine ragweed (Allpyral) extracts prepared from equal parts of low and giant ragweed pollen. Good or excellent clinical results were obtained in most patients with a minimum of reaction, notably constitutional ones, even when the interval between injections was quite prolonged. Seasonal asthma rarely occurred in the treated patients. In the author's opinion, the advantages offered by these extracts, notably their relative safety and at least equal clinical effectiveness, seem to warrant their preference over similar aqueous ragweed extracts currently employed or over attempted modifications of aqueous extracts.