IgE-sensitization to SUX, MOR and PHO was detected in Norway but not in Sweden. One possible explanation is the unrestricted use of cough mixtures containing MOR derivatives in Norway.

Fifteen out of 18 sera tested positive for MCT and/or specific IgE against neuromuscular blocking drugs (NMBDs). Ten of the 18 patients experienced an IgE-mediated anaphylactic reaction to NMBDs during anaesthesia, verified by detection of specific IgE and elevated levels of MCT.

This international prevalence study lends additional support to the PHO hypothesis and, consequently, that continued use of drugs containing this substance should be seriously questioned. The results also indicate that other, yet unknown, substances may lead to IgE-sensitization towards NMBAs.

Sixty dust samples from schools in Norway were analysed for major allergens from cat and mite after sampling with the regularly used vacuum cleaners for 5 days and with a new model vacuum cleaner for 10 days, respectively. The major feline allergen Felis domesticus allergen I (Fel d I) was detected in all the classrooms, with ranges from 12 to 16,840 ng/m2 floor area. The mean Fel d I concentration was about 11 times higher per unit area carpeted floors as compared with smooth floors after the 10 days sampling period. Mite allergens Dermatophagoides pteronyssinus allergen I (Der p I) and Dermatophagoides farinae allergen I (Der f I) were detected in very low concentrations, with ranges from < 1 ng to 104 ng/m2 floor area. These findings suggest that the school is a protective environment against mite infestation, while the prevalence of cat allergens in classrooms seems higher than previously assumed. Basophil histamine release was measured after provocation with 20 dust extracts from 10 different schools. In nine of the 10 schools examined, the basophil histamine release caused by challenge with carpet dust was higher than the corresponding release with smooth floor dust. The calculated floor areas in each school in which dust led to 15% histamine release were from 2 to 55 times larger for smooth floors compared with carpeted floors. These results emphasize previous findings regarding higher allergen concentrations in classrooms with carpeted floors.