[Therapy of hayfever and pollen asthma in children with a new, modified allergen extract].

During a period of 3 years a controlled and prospective study was performed, in which 20 children with pollinosis and pollen asthma (grass pollen) were treated either with a new modified allergenic extract (preparation I: Purethal) or with a standard semi-depot extract (preparation II: Depot-HAL) from the same producer. During the pollen season symptoms, side effects, additional medication, and pollen counts were registered. 20 patients were treated perennially: 5 with preparation II and with reduction of the doses during the pollen season (group A: treatment during 3 successive years), 15 without reduction of the doses during te season with preparation I (group B, 8 patients: treatment during 3 successive years; group C, 7 patients: treatment during 2 successive years). Patients in all groups showed more symptoms in May and June. In the groups B and C less symptoms were recorded. Especially, the score of asthma symptoms decreased. However, the need for additional medication was somewhat higher in these groups as compared to group A. The differences were not statistically significant. In 50% of the children no local side reactions were observed after the subcutaneous injections. In the groups B and C the number of late local reactions after 6 to 8 hours was somewhat higher. The patients treated with preparation I did not show an increase of allergen-specific IgG during the pollen season. The relative contribution of allergen-specific IgG1 and IgG4 to total specific IgG was lower in the blood samples of these patients as compared to those of group A. The efficacy and the therapeutic safety of the two preparations are comparable. Preparation I has a number of practical advantages, especially in the treatment of children.