Of the techniques which are usually used for the in vitro etiologic diagnosis of determined allergic processes, it is the RAST technique which is most widely used for determining specific
antibodies of the
IgE class. On the other hand, also of interest is the quantification of total
IgE in these patients. We have studied 80 allergic and non allergic patients in order to evaluate the possible correlation between the Prick and the RAST tests applied to different
allergens such
house dust. Dermatophagoides pteronyssinus and Dermatophagoides farinae. The patients were distributed in four groups in relation to the clinical history and serum levels of total
IgE, as follows: Group I: Patients with positive clinical history and increases levels of total
IgE. Group II: patients with positive history and normal values of total
IgE. Group III: patients with negative history and increased levels of serum
IgE, and Group IV with non atopic subjects with normal values of
IgE. The results show a high correlation between both tests for house dust mite
allergens in the group I. The relation to inferior in the group II. As far as
house dust is concerned, there is no correlation between the cutaneous test in the RAST test even in the group with positive clinical history. The data observed with house dust mites suggest a relation between the clinical history and the cutaneous test and also between the RAST and the levels of total serum
IgE. These relations are not fund with
house dust. It is discussed the validity and applications of both tests to the diagnosis of
immediate hypersensitivity reactions to house dust mites and
house dust.