Month of birth and grass pollen or mite sensitization in children with respiratory allergy: a significant relationship.

This report describes a retrospective analysis of the month of birth distribution of 2124 children with respiratory allergy in the Rome district between 1964 and 1985, in comparison with the total live births in the same district over the same period. Of the 2124 children, 1685 had positive skin tests and/or RAST only to mites, and 439 only to grass pollen (P much less than 0.001). A significant relationship was found between grass or mite sensitization and the month of birth. A high proportion of children born in June-September had mite allergy (P less than 0.005), and even higher was that of those born in March-May with grass sensitivity (P much less than 0.005), compared with the total live birth distribution in the Rome district in the same years as the children examined. These results are consistent with the idea that allergy may be associated with a period of susceptibility to sensitization in early infancy.