Flu (Influenza)

The flu is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness. It can also cause death in severe cases. The flu can affect your lungs when you have asthma. It can cause inflammation (swelling) and narrowing of your airways. These changes could trigger asthma symptoms, an asthma episode or an asthma attack. If you have asthma, defending yourself against the flu is very important.

Most healthy people recover from the flu without problems. Having asthma puts you at risk of serious health problems from the flu. If you develop flu-like symptoms, contact your doctor right away.

Special Information for People With Asthma

  • If you have asthma, get the flu shot. Do NOT get the nasal spray vaccine. The nasal spray could trigger asthma symptoms or an asthma attack.
  • Flu viruses change from year to year. So the flu vaccine changes each year. Get a flu vaccine every year when they become available.
  • If you have asthma and get the flu, see your doctor right away.  You are at greater risk of becoming severely ill with health problems from the flu very quickly.
  • If you care for children with asthma, get the flu vaccine to protect them.
  • The vaccine is safe. If you have asthma, the risks are far greater not getting the vaccine.

Special Information for People With Allergies

If you have ever had either of the following, you should check with your allergist to ask whether the flu vaccine is safe for you:

  • A life-threatening allergic reaction after a dose of flu vaccine
  • A severe allergy to any part of a flu vaccine

Egg Allergy and Flu Vaccine
Egg allergy is no longer a reason to avoid the flu vaccine. It is safe for ALL people with egg allergy to receive an annual flu shot. This is true no matter how severe your egg allergy was in the past. This includes anaphylaxis (a severe allergic reaction) to egg. Several research studies in the past four years have shown the injectable influenza vaccine (flu shot) is safe for those with egg allergy. The Centers for Disease Control (CDC), American Academy of Pediatrics, and American Allergy and College of Allergy, Asthma, and Immunology all have updated their recommendations.

flu vaccine

Latex Allergy and Flu Vaccine
If you have a latex allergy, check with your doctor before getting a flu vaccine. Latex could be in the flu vaccine vials or the syringes used to give the flu shot.

Severe Allergic Reactions 
Allergic reactions (including anaphylaxis) after flu vaccination are serious but rare.

Common Flu Symptoms

The flu usually starts suddenly and may include these symptoms:

  • Fever (often very high, 101 or above)
  • Headache
  • Extreme tiredness, chills
  • Constant cough
  • Sore throat
  • Runny or stuffy nose
  • Body aches in bones and/or muscles

Diarrhea and vomiting also can occur, but are more common in children. These symptoms are referred to as “flu-like symptoms.” Many different illnesses like the common cold, allergy symptoms and asthma symptoms can sometimes be similar and confusing. Talk with your doctor to get a proper diagnosis.

Common Emergency Flu Symptoms

There are some emergency signs that require immediate medical care.
 

For children, emergency signs include:

 

  • Rapid breathing or difficulty breathing
  • Blue skin color
  • Not drinking enough fluids
  • Not waking up or not being conscious
  • Being irritable and difficult to comfort  
  • Flu-like symptoms seem to improve but return with worse fever and cough
  • Fever with a rash

For adults, emergency signs include:

  • Rapid breathing or difficulty breathing
  • Pain in the chest or abdomen
  • Sudden dizziness
  • Confusion
  • Severe or persistent vomiting

How Does the Flu Spread?

Unlike asthma, the flu is contagious. The flu spreads from coughing and sneezing. It usually spreads from person to person. You can also get the flu by touching something with the flu virus on it, then touching your mouth or nose. You can spread the flu before you know you’re sick and when you are sick.

Diagnosing the Flu

There are tests that can tell if you have the flu. But testing must be done within the first three days of illness. You may also need a doctor’s exam to tell if you have an infection that is a complication of the flu.

Treating the Flu

There are antiviral drugs approved to treat flu. Talk to your doctor about these prescription medicines. Antiviral treatment must be started within two days of illness. If you get flu-like symptoms, seek medical care right away.

Other treatment tips are to get plenty of rest, drink plenty of liquids and avoid using alcohol and tobacco. Also, you can take over-the-counter medicines to relieve flu symptoms.

Preventing the Flu

Flu season can last from fall through the spring. There are some easy things you can do to avoid getting the flu:

  • If you have asthma, you should get the flu shot when it is available each year. Do NOT get the nasal spray vaccine. The nasal spray could trigger asthma symptoms or an asthma attack.
  • Wash hands often with soap and warm water, particularly after coughing or sneezing. If you don’t have access to running water, use an alcohol-based hand cleanser.
  • Don’t touch your eyes, nose or mouth. This is how germs often spread.
  • Stay away from people who are sick.

There are also some easy things you can do to avoid spreading respiratory illnesses like the flu:

  • Cough or sneeze into your inner elbow when you don’t have a tissue.
  • Wash hands often with soap and warm water, particularly after coughing or sneezing. If you don’t have access to running water, use an alcohol-based hand cleanser.
  • Don’t touch your eyes, nose or mouth. This is how germs often spread.
  • If you get the flu, stay home from work or school.
     

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Medical Review October 2015.