Dust mites are one
of the most common allergens throughout the world. They grow best indoors in warm, humid
environments. Their growth is hindered
in very dry climates. Carpeting and
upholstered furniture are the major sources in the classroom, but mattress and
pillows are the major source in the home.
Cats and dogs are
the most common cause of pet allergies.
In cats, the allergen is present in skin secretions and saliva, and
isn’t part of the hair. The substance dries
on the hair from skin secretions or when the cat licks its hair. In the case of the dog, the allergen is
contained in skin scales and hair. Pet
allergens are very tiny particles and they float in the air for prolonged
periods of time, and stick to whatever they contact. In classrooms without pets, the clothing of children
who have pets at home can be a major source of allergen, enough to cause
symptoms in allergic children.
Pollens are
usually encountered outdoors. The types
of pollen varies by the time of year.
Tree pollen is usually present in the early spring, grass pollen in the
late spring and early summer, and weed pollens in late summer and early
fall. Children participating in PE or
recess during high pollen days can have allergy problems.