Is it the Flu, COVID-19, or Allergies?

Clinical Contributors to this story:
Nancy J. Vacca, MD, MBA, FAAFP
Medical Director

Flu, COVID-19, and allergy symptoms can feel very similar. It can be helpful to know the difference so you can get the right treatment at the right time. Here’s an overview of each and notes on when to call your doctor.

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Flu

Influenza (also known as “flu”) is a contagious respiratory illness caused by influenza viruses. Influenza A is generally more common and more severe than influenza B. Both strains can cause mild to severe illness and, at times, can lead to death.

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COVID-19

People with COVID-19 have a wide range of symptoms ranging from mild symptoms to severe illness. Symptoms may appear 2-14 days after exposure to the virus. Symptoms may start as mild, and some people will progress to more severe symptoms. COVID-19 spreads more easily than the flu and can cause more severe illness in some people. It may also take longer to show symptoms, and you may be contagious for longer periods of time.

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Allergies (Hay Fever)

Depending on the allergen, allergy symptoms vary seasonally or year-round, affecting up to 60 million people ever year in the United States. Symptoms include sneezing, runny nose, and congestion.

SYMPTOM	Flu	COVID-19	Allergies (Hay Fever)
Fever	Usual, sudden onset, high, (100-102 °F), sometimes higher, especially in young children); lasts 3-4 days	Usual, can vary in intensity (how high) and duration (how long)	Very Rare
Headache	Sometimes	Sometimes	Sometimes
Body Aches	Usual; often severe	Usual; often in the head and neck	Very Rare
Fatigue (tiredness), Weakness	Usual	Usual, can be long-lasting	Sometimes
Stuffy, Runny Nose and Sneezing	Sometimes	Sometimes	Usual
Itchy/Watery Eyes	Uncommon	Uncommon	Usual
Sore Throat	Sometimes	Common	Sometimes
Cough	Common	Common	Sometimes
Change or Loss of Taste or Smell	Sometimes	Common, can be long-lasting	Very Rare
Shortness of Breath/Difficulty Breathing	Sometimes, as a result of coughing fits	Sometimes, feeling breathless or winded	Very Rare
Nausea/Vomiting/Diarrhea	Sometimes, more common in children	Sometimes, can occur in any age	Very Rare
TREATMENT	Get plenty of rest and stay hydrated Stay home until you are better Aspirin (ages 18 and up), acetaminophen, or ibuprofen for aches, pains, and fever Ask your doctor about antiviral medications Antibiotics will not treat the flu	Get plenty of rest and stay hydrated Stay home until you are better Aspirin (ages 18 and up), acetaminophen, or ibuprofen for aches, pains, and fever. Ask your doctor about antiviral medications Antibiotics will not treat COVID-19	Avoid allergens (things that you’re allergic to) Over-the-counter antihistamines, nasal steroids, decongestants (talk to your doctor)
PREVENTION	Get the flu vaccine each year! Wash your hands often. Avoid close contact with anyone who has the flu.	Get the COVID-19 vaccine and boosters recommended for your age group! Wash your hands often. Avoid close contact with anyone who has COVID-19.	If possible, stay indoors. Common Texas outdoor allergens include ragweed, elm, mountain cedar, and oak pollen. Common indoor allergens include dust mites, pet dander, and pollen tracked in from outdoors. Try not to rub your nose or eyes. Use an air purifier.
WHEN TO GET HELP	Call 911 or go to the nearest emergency room: Trouble breathing Persistent pain or pressure in the chest or abdomen Chest pain, ribs pulling in with each breath in children Severe muscle pain Dehydration (not urinating) Fever or cough that improve, but then return or get worse Fever above 104°F that is not controlled by fever-reducing medicine Long-lasting dizziness, confusion, or inability to wake or stay awake Bluish lips or face	Call 911 or go to the nearest emergency room: Trouble breathing Persistent pain or pressure in the chest New confusion Inability to wake or stay awake Depending on skin tone, lips, nail beds, and skin may appear pale, gray, or blue	Call your primary care provider or go to an urgent care center: Sinus infection Ear infection

Recognizing the differences between the flu, COVID-19, and allergies can help you decide on the proper treatment and reduce the risk of complications.

If you are unsure about your symptoms, calling your doctor for advice is always a good idea. Community First also offers Members a 24/7/365 Nurse Advice Line staffed by Registered Nurses who can tell you what you can do at home to start feeling better faster and help you decide where to go for care.

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