Sneezing, a runny nose and an itchy throat can occur with allergies and respiratory infections, making it difficult to determine the cause from symptoms alone.
Allergic rhinitis, commonly known as hay fever, often causes sneezing, a runny or stuffy nose, itchy eyes and an itchy nose or throat. COVID-19 can also cause a runny or stuffy nose and sore throat, along with symptoms such as fever, cough, fatigue, headache and muscle or body aches.
Because the symptoms overlap, having a runny nose or sneezing does not by itself establish that someone has COVID-19.
Itchy eyes
Itchy, watery or red eyes are more commonly associated with allergies than with a cold. Mayo Clinic lists itchy and watery eyes among the typical symptoms of hay fever, while the American Academy of Allergy, Asthma & Immunology identifies itchy eyes and sneezing as common features of allergic rhinitis.
COVID-19 can sometimes cause eye symptoms, including redness, tearing and itching, but these are not enough on their own to determine whether a person has the infection.
Fever and body aches
Fever and muscle or body aches can occur with COVID-19 and other viral respiratory infections. They are not typical features of hay fever.
Mayo Clinic notes that fever does not occur with hay fever, while the CDC lists fever or chills and muscle or body aches among possible COVID-19 symptoms.
The absence of fever, however, does not rule out COVID-19 because people can experience the infection without every listed symptom.
Sore or itchy throat
A sore throat can occur with COVID-19. Allergies can also cause throat irritation, particularly when mucus drains down the back of the throat, a condition known as postnasal drip.
An itchy throat, especially when accompanied by sneezing, a runny nose and itchy eyes, is more consistent with allergic rhinitis than with a respiratory infection.
Difficulty swallowing or significant throat swelling requires medical attention rather than assuming the symptoms are caused by allergies.
When symptoms overlap
COVID-19 and allergies can both cause nasal congestion and a runny nose. Allergies commonly produce symptoms after exposure to a particular allergen and can continue for as long as the exposure persists.
A pattern that repeatedly appears around particular environmental triggers can point toward allergies, but symptoms alone cannot provide a definitive diagnosis.
Other conditions can also cause similar symptoms. Nonallergic rhinitis, for example, can cause sneezing, a stuffy or runny nose and mucus in the throat without being caused by an allergy.
Testing can help identify COVID-19
When COVID-19 is a possibility, testing can help determine whether the symptoms are caused by SARS-CoV-2, the virus that causes COVID-19.
The CDC says viral tests detect current infection. These include antigen tests and nucleic acid amplification tests such as PCR. A negative rapid antigen test does not always rule out infection, particularly when someone has symptoms.
People who have persistent or troublesome allergy symptoms can also see a health care professional or allergist. Allergy testing may help identify the substance triggering the reaction.
The key difference is that symptoms such as sneezing, a runny nose and throat irritation are not specific to one condition. A person’s symptom pattern, exposure history and, when appropriate, medical testing provide a more reliable way to determine the cause.
