March 17, 2006

Middle Park Times

Doctors not immune from the common cold


I was speaking with a co-worker the other day.  She was telling me about her daughter’s recent cold and how it progressed over the week.  My co-worker said that the cold started with a sore throat, then her daughter developed a fever, progressed to having discolored nasal discharge, and finally to a bad cough.  We spoke about some of the common beliefs about colds and when a person should seek a health care provider to evaluate their cold.  A couple of days later I was lucky enough to start experiencing all of these stages myself with my very own cold.


How often do people get colds?   The average adult will be infected with the common cold 2-3 times per year, while the average child will have 6-8 infections per year.  Some kids get an infection on average every month in the wintertime (especially ones that attend daycare or are just starting school).  In the US, there are an estimated 1 billion common-cold infections per year.


What causes the common cold?  There is a collection of different types of viruses that cause the common cold, and within each virus type there are many subtypes.  This means that there are thousands of unique viruses that can give you a cold!  If only one virus was responsible for the common cold, your body would develop immunity to the virus after the first infection and then would never get a cold again (or at least you wouldn’t feel poorly again).  However, the large number of viruses as well as their ability to mutate (change) is the reason that adults continue to get infected later in life.  The three most common viruses that can cause the common cold are the rhinoviruses, the coronaviruses, and the respiratory syncytial virus.  These account for over 50% of the common cold cases.  Bacteria do not cause the common cold, but sometimes can appear after the common cold has suppressed the body’s immune system.


What are the symptoms and progression of the common cold?  Since the common cold is so “common”, most of us know and understand the symptoms of an infection.  A person is infected by a virus, and then the virus incubates for a period between 24 and 72 hours expires before any symptoms occur.  The symptomatic phase of the common cold lasts between 3 to 7 days, but in some cases can last up to 2 weeks.  The first day is usually starts with nasal congestion, rhinorrhea (“runny nose”), and sneezing, but can also start with a sore or "scratchy" throat.  The sore throat is usually short lived, and nasal symptoms predominate by the second and third day. A cough typically becomes troublesome on the fourth or fifth day of illness, by which time the nasal symptoms are less severe.  Other symptoms, that vary depending on the type of virus, can include: ear pressure or pain (over 70% of cases), eye irritation (60% of cases), fevers (50% of cases), muscle aches (45% of cases), and enlarged lymph nodes (45% of cases).  The progress from a “head cold” (nasal congestion) to a “chest cold” (cough) is the normal progression of the common cold and does not indicate a worsening of the infection.  The color of nasal discharge (“snot”) also is not indicative of a worsening of the infection.  The first clear colored nasal discharge is the body’s first response against the invader by simply increasing mucous production to try and “flush out” the virus. As the body’s immune gets involved, the first to respond is the antigen presenting cells which kill off cells wholesale, including many cells that are not infected.  This left over cellular debris along with the contents of the antigen presenting cells changes the color (white, yellow, and green) and consistency (thick) of the nasal discharge.  As the immune system hones in on the invader, the lymphocyte cells make precision strikes and take out only infected cells, which again changes the color and consistency of the discharge.  The same is true for the sputum (“spit”) that is produced with a cough during the cold (no production, then clear, then colored/thickened sputum).


So, what complications can occur after succumbing to the common cold?  The most frequent complications include ear infections, sinus infections, and lower respiratory infections (bronchitis or pneumonia).  Many of these complications are actually new viruses that have infected

a person after the first virus has suppressed the person’s immune system.  Very rarely, a bacterial infection occurs after onset of the cold.  A study performed in 2004 found that acute bacterial sinusitis after the common cold occurs less than 2% of the time.  The study also reported that only 10% of the people with a confirmed bacterial sinusitis who received antibiotics improved more quickly (1.6 days on average) than people that did not receive antibiotics.  The other 90% healed at the same rate as the group that did not receive antibiotics.  In children, only 5% of cases of the common cold result in an ear infection with over 50% of these cases due to a viral infection of the ear.  Lower respiratory infections are again typically viral infections (RSV, rhinoviruses, or coronaviruses), but rarely can be caused by a bacterial infection.


Treatment of the common cold focuses on the relief of symptoms.  For nasal congestion, either a decongestant spray (e.g., Afrin) or pill (e.g., Sudafed) is effective but should only be used for a few consecutive days and not more than 5 to 7 days.  An antihistamine (e.g., Benadryl) can help with sneezing and nasal discharge symptoms. For nighttime cough, codeine is modestly effective, and daytime cough may be slightly improved with guaifenesin (e.g., Mucinex).  Heated and humidified air can reduce nasal congestion symptoms and improve breathing.  Sore throat and headaches are best treated with Tylenol and throat lozenges (for children with possible flu symptoms do not give aspirin, ibuprofen, or products containing aspirin – like Pepto Bismol, since they can develop Reyes syndrome).  Various items that do not help cold systems (according to medical research) include: zinc, Vitamin C or E, Echinacea, anti-viral medicines, and antibiotics.  Yes, it’s true; antibiotics do not help cure the common cold.  A study performed by Kaiser Permanente of Northern California found that antibiotics even delay healing of a viral infection by up to 2 days.


So, when should you see a health care provider during a cold?  There is no specific answer to this question.  The color of nasal discharge, the height of the fever, the length of illness, or the persistence of cough is not predictive of an illness that needs medical attention.  Typical common cold symptoms should be treated with over-the-counter medicines (as listed above) to help alleviate those symptoms, but no medications have ever been shown to cure the common cold more quickly than no treatment at all.  If you are uncertain that an illness is truly the common cold (e.g., only a sore throat and fever), are having significant problems with breathing, are feeling worse even after 5 to 7 days, or have improved for 1 to 2 days and then again worsen, then you should seek medical advice from your health care provider.  Special cases exist that necessitate that a person sees their health care provider immediately.  These cases include a person with a history of a lung disease (COPD, asthma, etc), an infant less than 6 months of age, or an immunocompromised person (HIV, transplants, chemotherapy, etc).


How can you avoid being infected by the common cold in the future?  The best option is to avoid people who display symptoms of a cold.  However, this is not always possible, and since an infected person may take up to 72 hours before they show symptoms, you may not even know they are infectious.  The best alternative to avoid catching the common cold is to wash your hands frequently.  Most infections occur by a person touching an infected person (or their eye, nasal or oral excretions) and then touching their own eyes, nose, or mouth.  So, by washing your hands frequently and not touching your own eyes, nose, or mouth you can avoid most of the risk of infection.


You may be wondering how I dealt with my cold.  Well, I practice what I preach.  I used pseudoephedrine (in my case it was DayQuil) and nasal saline washes for my nasal congestion.  For my sore throat I used throat lozenges (Halls).  I used ibuprofen for fevers and muscle aches.  I did not take any antibiotics, but I did take some Vitamin C and Echinacea (even a doctor can hold on to some superstitions).  My cold improved within 6 days and was gone by 8 days.