Can allergies cause an itchy throat?

How allergies cause it

Each spring, summer and fall, trees, weeds and grasses release tiny pollen grains into the air, and some of that pollen ends up in your nose and throat, where it can trigger hay fever.² Hay fever, or allergic rhinitis, develops when the immune system recognizes and overreacts to something in the environment.¹

Hay fever brings itching, usually in the nose, mouth, eyes or throat, and it can also make the eyes red and watery.¹ Seasonal symptoms can occur in spring, summer and early fall.¹ Tree and grass pollen are the most common spring triggers, while ragweed, other weeds and outdoor mold are common in the fall.¹ Dust mites, pet hair or dander, cockroaches and mold can cause symptoms all year.¹

Pollen allergy can also bring postnasal drip, mucus that runs from the back of the nose down the throat.³

Itching after eating raw fruit

Some people with a pollen allergy notice an itchy mouth or scratchy throat after eating certain raw fruits, vegetables or tree nuts.⁴ This is pollen food allergy syndrome, also called oral allergy syndrome: the immune system recognizes the pollen and similar proteins in the food and directs an allergic response to it.⁴ AAAAI says it happens in up to 50 to 75% of adults allergic to birch tree pollen.⁵

ACAAI links birch pollen with apple, almond, carrot, celery, cherry, hazelnut, kiwi, peach, pear and plum; grass pollen with celery, melons, oranges, peaches and tomato; and ragweed pollen with banana, cucumber, melons, sunflower seeds and zucchini.⁴ In many people the reaction gets worse during the season of the pollen in question.⁵

Symptoms usually appear immediately after eating, though in rare cases they start more than an hour later.⁵ They usually fade quickly once the fruit or vegetable is swallowed or taken out of the mouth.⁴ Cooked versions of the same foods are usually tolerated, because heating distorts the proteins.⁴

Allergies or something else?

Viruses, like those that cause colds or flu, are the most common cause of a sore throat.⁶ Strep throat, caused by group A Streptococcus bacteria, is another cause, and so are allergies and smoking or secondhand smoke.⁶

Hay fever shares many symptoms with a cold, but it is not caused by a virus or bacteria.¹ Its symptoms can begin immediately after exposure, while a cold most likely begins a day or two after exposure to the virus and can last a few days to a week.¹ Allergy symptoms last as long as the allergen is around.⁷

When to see a doctor

Talk to a healthcare provider about a sore throat, especially one with difficulty breathing or swallowing, blood in saliva or phlegm, excessive drooling in young children, dehydration, joint swelling and pain, or a rash.⁶ Symptoms that do not improve within a few days or get worse are another reason to go.⁶

If the throat feels tight, the voice turns hoarse, or breathing or swallowing becomes hard during a reaction to a food, get emergency care: FARE counts these as severe symptoms, and severe reactions can quickly progress to anaphylaxis.⁸

See an allergist if you’re always getting an itchy mouth after eating the same raw fruit or vegetable.⁴ A reaction that goes beyond the mouth after eating a fresh fruit or raw vegetable means that food could be a risk for anaphylaxis.⁴ AAAAI also advises talking to a physician if these symptoms cause significant throat discomfort, get steadily worse, or come from cooked fruits and vegetables or from nuts.⁵ For hay fever itching, ACAAI says consulting an allergist is the most effective way to diagnose allergic rhinitis.¹