With indoor allergens the chemical formaldehyde was identified as a major culprit.

Classroom settled dust samples were analyzed for the presence of common indoor allergens.

Objective: To examine relationships between room characteristics and concentrations of indoor allergens in homes of suburban asthmatic patients.

Especially after a long winter during which indoor allergens like dust and pet hair may have piled up.

Sensitization was more prevalent for indoor allergens than for outdoor allergens in all groups determined according to diagnosis or age.