Abstract
A double-blind clinical trial of hyposensitization with aqueous extracts of Dermatophagoides pteronyssinus (the house-dust mite) and human skin scales showed a substantial improvement in symptoms in 11 asthmatics allergic to house dust treated with the D. pteronyssinus extract and a reduction in their need for other therapy. Five patients were well for a year but six relapsed. These results contrasted with the generally unfavourable course of the patients treated with the extract of human skin scales. Asthma due to house-dust allergy may be substantially improved by hyposensitization with D. pteronyssinus extract.