Hyposensitization in childhood hay fever. A comparison of refined and whole timothy extracts.

Abstract

Thirty-six children with well-defined criteria for hay fever (mean age 8 and range 4-15 years) were allocated at random for hyposensitization (HS) with a refined (R) or whole (W) timothy pollen extract during 3-4 years. HS was performed as rush HS with the patients hospitalized for about 1 week and thereafter with monthly injections. Scores for symptoms and antihistamine use were recorded during the season before HS and all seasons during HS. Skin and conjunctival tests were made at the start of HS and postseasonally. Blood samples for IgE and IgG measurements were drawn before and during rush HS and pre- and postseasonally each year. The R-group patients tolerated a higher allergen dose at the end of the rush HS than the W-group ones. They also demonstrated a higher, significant increase in total and specific IgE levels within 7 days and specific IgG levels within 60 days after the start of HS. In both groups postseasonal increases in total and specific IgE levels were seen. The IgG levels increased successively during the treatment. The most remarkable difference between the groups was in scores for symptoms and antihistamine use, which in group R decreased significantly while they increased significantly in group W. Based on these data we recommended that HS, if indicated, should be performed with purified allergen extracts.