[Correlation of allergy positivity for the tests of gramineas between tribes and species].

In a sample of 190 Costa Rican allergic patients and 100 non atopic subjects there was a positive correlation of positivities in skin prick tests to individual Poaceae species and to the Tribe. The exceptions were Panicum maximun, Panicum molle, and Holcus lanatus, because they presented higher individual positivities. A table of correlations among tribes is included. Skin prick tests for Poaceae pollens should be organized by tribes to prevent a 25% of false negative cases.