Aren't they too young for hay fever?

Not by preschool. Seasonal allergies need a few seasons of exposure before they develop, which is why they typically appear around ages three to five rather than in infancy.

Can I just use the antihistamine we have in the house?

Check first. Several common over-the-counter antihistamines and most decongestants are not suitable for preschoolers, and the age cut-offs are not intuitive.

How do I know it's not sinusitis?

Sinusitis usually brings facial pain or pressure, thick discolored discharge, and often a fever, and it does not itch. A persistent clear, itchy, feverless nose that tracks the seasons points elsewhere.

When it happens · 4 min read

A cold that has lasted six weeks

They have had a cold since what feels like the start of spring. It is not getting worse, it is not getting better, and preschool keeps sending them in because there is no fever and nothing to exclude them for.

At some point it is worth asking whether it is a cold at all. Seasonal allergies usually show up in the preschool years, once a child has had a few seasons of exposure, and they routinely get filed as bad luck with viruses for a year or two first.

Last updated August 17, 2026

Telling it from a cold

The discharge is clear and watery, and it stays that way. A cold thickens, changes color and resolves over about ten days; allergies do not follow that arc.

The itch is the giveaway. Itchy eyes, itchy nose, itchy throat, and often the horizontal crease across the bridge of the nose that comes from pushing it upwards all day.

No fever. Preschoolers with colds usually run one at some point. Allergies do not cause fever, and a fever means look again.

It repeats. Same weeks of the year, every year, or it flares reliably around a particular animal or a particular dusty room.

What actually helps

Reducing exposure where it is practical rather than where it is total: windows shut on high-pollen days, a rinse and a change of clothes after a long stretch outside, hair washed before bed so the pollen does not spend the night on the pillow.

Antihistamines suitable for the age, and steroid nasal sprays where they are indicated. Ask rather than guessing — several over-the-counter options are not appropriate for a four-year-old, and the dosing is not simply scaled down from adult.

Saline nasal rinses, which are unglamorous, cheap and genuinely effective.

Treating it properly matters beyond comfort. A child who cannot breathe through their nose does not sleep well, and that shows up as behavior and concentration problems all day rather than as an obvious nose complaint.

Worth raising with a doctor

Symptoms interfering with sleep, or with preschool.

Wheeze, a cough at night, or getting breathless on running, alongside the nasal symptoms. Allergy and asthma travel together and either one can reveal the other.

Eczema that flares at the same time of year.

No response to a reasonable trial of treatment, which sometimes means the diagnosis itself needs revisiting rather than the dose increasing.

Common questions

Aren't they too young for hay fever?: Not by preschool. Seasonal allergies need a few seasons of exposure before they develop, which is why they typically appear around ages three to five rather than in infancy.
Can I just use the antihistamine we have in the house?: Check first. Several common over-the-counter antihistamines and most decongestants are not suitable for preschoolers, and the age cut-offs are not intuitive.
How do I know it's not sinusitis?: Sinusitis usually brings facial pain or pressure, thick discolored discharge, and often a fever, and it does not itch. A persistent clear, itchy, feverless nose that tracks the seasons points elsewhere.

If it's this, not that

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