27 Jan Flu Vs. Common Cold

One of the more common questions I get during flu season is, “how do you tell the difference between Flu and Common Cold?” Sounds like an easy question but there is not always a clear way to differentiate them.  Typically both incubate for 2-3 days before symptoms present and symptoms will last for 4-7 days.  They both can present with body aches, sore throat, runny nose, headache and cough.  They are both transmitted by particle droplets.

Influenza is most commonly spread by large droplets, meaning you need to be in close contact, approximately 6 feet.  The common cold is often spread not only by large droplets but also by much smaller droplets that can be aerosolized and spread over greater distances.  Most often both are spread by hand-to-hand contact, thus the importance of washing your hands regularly and keeping your hands away from your face.  Contaminated environmental surfaces can also transfer live viruses.

Flu is caused by the Influenza A or B viruses.  The ” Common Cold” can be caused by over 200 different subtypes of viruses, including the Influenza viruses in about 5% of the cases.

Fever is usually the differentiating clinical symptom.   Flu will usually cause a fever from 100-104F, however, flu can present without fever.  Clinically a high fever is the symptom we most often use to decide if somebody needs to be treated with anti-viral medications.  The Common Cold viruses typically don’t cause pneumonia, however, pneumonia is one of the common complications of influenza.  Influenza can directly cause pneumonia and increase the chances of getting a bacterial pneumonia.   You should think about the possibility of pneumonia when symptoms persist or increase instead of resolving within the usual timeframe.

Antibiotics don’t help uncomplicated flu or the common cold.  If flu is suspected Anti-viral medication should be started within 48 hours of the onset of symptoms.  A rapid flu test is not accurate enough to forgo treatment if the clinical presentation is consistent enough with flu.

The symptoms of a common cold can be treated in a variety of ways, but the only cure is time. “Runny nose” symptoms can be treated with decongestants such as Pseudoephedrine (Sudafed) and nasal steroid sprays (Nasacort and Flonase).  Expectorants and cough suppressants like Dextromethorphan (Robitussin) and guaifenesin (Mucinex) may help with a cough.  Echinacea has been touted as a treatment in the supplement industry, however, several rigorously designed trials have shown no benefit.  In the mid 1970’s zinc became a popular treatment.  Several questions have been raised about its unknown benefits and possible toxicities.  Vitamin C, D, and E supplementation have not been shown in randomized trials to be of any benefit.  Antibiotic therapy in uncomplicated upper respiratory tract infections is likely to cause more harm than good.  Antiviral medications have not shown enough benefit to warrant their use.  The best treatment is likely a warm bed, hot tea, your mother’s homemade soup, and a lot of TLC from a loved one.  No matter what you do you are likely to have symptoms for 4-5 days.

Here’s to the Journey!

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(David W. Ball, MD, an Internal Medicine physician, founder of NuVitality Health – a wellness education company, and co-founder of Life Changing Fitness – a fitness facility for Every Body)