Pollen count, symptom and medicine score in birch pollinosis. A mathematical approach

This study investigates the correlation between the daily birch pollen counts, hay fever symptoms and medicine scores. Fifteen birch pollinosis patients were studied during two consecutive birch pollen seasons. All had a positive history for birch hay fever and a positive skin prick test, nasal provocation test and/or conjunctival provocation test to birch pollen. The patients recorded daily symptom and medicine scores during February through May for two seasons. According to nasal/conjunctival sensitivity and medicine consumption the group was divided into three groups: very sensitive, sensitive, and fairly sensitive. The mathematical calculations were based only on the results from the two most sensitive groups. The relationship between symptom scores and medicine scores as a function of the pollen load was nonlinear. A mathematical model was calculated. It was found that simply adding symptom scores and medicine scores to a total symptom/medication score was not meaningful as a basis for a quantitative analysis. It was further shown that the response caused by a given pollen load decays exponentially with time and that this decay had a characteristic half-life period of about 1-2 days indicating a long-lasting effect, i.e. contribution of the late allergic reaction to symptoms. Both groups showed the development of increased medicine intake during the season for a constant pollen load. This indicates the development of a higher sensitivity to birch pollen during the season. The overall response was divided into characteristic levels based on dose-response relationships, and pollen concentration intervals for forecasting purposes are suggested.