Background: At present test tube allergy diagnosis is becoming increasingly more comparable to skin prick tests and is therefore increasingly more reliable, not only from an analytical point of view but also from a clinical one. The cost of test tube allergens has decreased over the years and the specific IgE dosage can quickly give a good diagnostic indication. Objective: To study the percentage of positive subjects for each individual allergen in cases of suspected allergy, the laboratory can easily identify, also by age bracket, the positivity for those well known allergens that are more commonly responsible for allergic pathologies by using the skin prick test. Our laboratory has studied the test tube diagnostic activity of 2002 and 2003. The inhaled allergens used to identify the positivity percentage were selected from those in our Allergy Unit and which literature identifies as those more commonly positive at skin prick tests. Methods: The positivity rate of specific IgEs (UniCAP100- Phamarcia) were analyses for two age brackets before and after the age of 12. The younger than 12 group was then subdivided further into pre-school age (3-5 years) and school age (6-12). Results: It can be stated that in the grass group, the seasonal allergens, the most commonly positive were cereals and pellitory, the latter increasing in adult age (above 12 years). In the tree group of seasonal allergens, positivity was found to increase in adult age for olive and cypress trees. The more commonly positive perennial allergens in the adult age (above 12) are dermathophagoides and cat. Below 12, there is a strong positivity to alternaria. Conclusions: Such test tube studies on IgE positivity are not only useful for better defining diagnostic patterns to give an initial idea of suspected allergy, but also to highlight any changes in the IgE antibody count within different age brackets, with the possibility of documenting the progress of the pathology which is characteristic of the allergy in question