We studied 500 patients with an average age of 36.25 +/- 14.27 years and did the following tests: Intradermoreaction and prick tests, total IgE by PRIST and specific IgE by RAST. The antigens used for the study were the following: Lolium Perenne, Dermatophagoides pteronyssinus, and house dust. Of de 500 patients studied, 104 had a negative skin test and RAST. They also had a negative history of allergy. The other 396 patients presented a clinical history compatible with the diagnosis of allergy and were positive to skin test and/or RAST. A correlative study between the different techniques utilized in the diagnosis of these patients was undertaken. We observed significant higher levels of total IgE in the allergic than in the non-allergic group (p less than 0.001). The normal levels of total IgE in our environment were equal or inferior to 263.33 UI/ml. In the group of allergic patients, levels higher than 263.33 UI/ml were found in 49.27% of RAST positive patients and 46.35% in skin test positive patients. In the 295 patients studied with intradermoreaction, the correlation coefficients (r) were as follows: Lolium perenne r: 0.90; Dermatophagoides Pteronyssinus r: 0.54; house dust r: 0.14. The correlation coefficients (r) in the 101 patients studied with prick tests were the following; Lolium perenne r: 0.86; Dermatophagoides Pteronyssinus r: 0.82; house dust r: 0.48. As can be observed the prick tests gave overall better results than the intradermoreaction. On comparing the skin and RAST tests qualitatively we observed that in those patients studied by prick tests, 86.79% were pollen-positive in both trials.(ABSTRACT TRUNCATED AT 250 WORDS)