Allergies and Infections
Allergies in children are generally known to peak around
early adolescence. Apart from the common low to moderate allergic
conjunctivitis, some children also suffer from a more severe type
of allergic conjunctivitis that often affects the cornea as well
as the conjunctiva i.e. vernal kerato-conjunctivitis.
Its causes are often air-borne pollen or dust-mites, animal hair
etc. These allergies generally subside or are much improved by the
end of adolescence.
Infections of the conjunctiva can
develop more readily in the presence of allergy.
They can occur as a result of direct
contamination to the eye from external sources,
such as swimming pools or when the eyes are
rubbed. Infections can also stem from the sinuses
or nasal passages, which are more prone to
infection in the presence of inflammation due to
allergy or any type of irritant such as vehicle
emission pollution, smoke, dust etc.
The nasal passages or sinuses are the principal chronic
sources of infection to the eyes. This is the main cause of
the commonly seen chronic infective conjunctivitis. More
acute eye infections can also develop in the presence of acute sinusitis.
Another source of infection can be the lid margins. When the base
of the lashes is infected, a mild crusting or dandruff-like appearance
can develop and is termed blepharitis.
This condition is often caused by chronic rubbing of the eyes especially
in response to symptoms of irritation from a pre-existent conjunctivitis.