Sensitization to grass pollen allergen molecules in a birth cohort - Phl p 4 as early indicator of grass pollen allergy.

nPhl p 4 is a hitherto unrecognized early indicator of grass pollen allergy, in addition to Phl p 1. To identify grass pollen sensitization and predict later ARg, allergen molecules are of added value to timothy extract and may help clinicians improve prediction of grass pollen allergy.