Metachromatic cells in nasal mucosa after allergen challenge

Metachromatic cells in the nasal mucosa were studied in relation to symptoms in 16 schoolchildren and 11 adults with hay fever who were challenged with pollen outside the pollen season, using either a gentle scraping-cytocentrifugation method for collection of mucosal specimens or biopsies. There was a temporary redistribution of metachromatic cells towards the mucosal surface appearing 5-24 h after challenge, with a correlation between the quantity of metachromatic cells and symptom scores. Thus, a single exposure to high doses of allergen may contribute to priming in susceptible individuals.