Respiratory Tract Infections: Colds, Flu, Sinus Infections

 

Respiratory tract infections are the most common reason for a same-day appointment in most primary care physician offices.  What exactly do I mean by a respiratory tract infection?  An illness that involves congestion of the nose or sore, scratchy throat or cough or congestion or sneezing or all of these.  They are the most common illness normal healthy people experience. 

For a video of Fred Ott sneezing, which was one of the first moving pictures ever made:

http://www.youtube.com/watch?v=8PaJ1r0udvQ


Most people catch some type of respiratory illness at least once a year, many of us perhaps twice or three times a year.  I personally can count on getting two or three colds a year.  I swear I always get them just as I'm leaving on vacation! (That actually did happen just two weeks ago as I was leaving on our spring break trip.)

What are the actual illnesses that make up what we refer to as respiratory infections?  I will divide the illnesses into the upper respiratory tract(nose/throat/sinuses/ears) and lower respiratory tract--trachea, bronchial tubes, and lungs.

Upper Respiratory Tract:  We call these "URIs" or upper respiratory infections.  First and foremost:  Colds, which are caused by numerous viruses of the rhinovirus and adenovirus families.  Then influenza (also caused by viruses, belonging to two types--influenza A and influenza B).  Strep throat, which is, of course, caused by a specific type of bacterium called streptococcus.  Then there are ear infections (caused by either viruses or bacterial infections) and sinus infections (also caused by viruses and bacterial infections.

Lower Respiratory Tract:  The same viruses that cause colds and influenza can affect the lower respiratory tract, causing coughs, chest congestion, and phlegm or mucus production.  "Bronchitis" is a term I consider a "garbage can" diagnosis because it is simply a descriptor--it means the bronchial tubes are inflamed.  It can be applied to any illness where a cough is the primary symptom. The most serious of the lower respiratory tract infections would of course be pneumonia, which can be caused by viruses, bacteria, or in rare cases even fungal infections.

Let's take these one at a time:

Colds: 
Colds have a pretty predictable pattern in most people.  The very first symptoms are usually a sense of discomfort in the back of the throat--often a dryness or scratchiness or just achiness, along with perhaps some unusual fatigue.  Usually within 24 hours the cold becomes obvious:  a more significant sore throat, deepening voice (from swelling of the vocal cords), increasing nasal congestion, post-nasal drainage (mucus draining down the back of the throat), and a general sense of illness--fatigue, low grade headache, and what we term "malaise"--just not feeling well.  Some people note feeling hot and cold, or more sweaty, or more sensitive to environmental temperature. It is fairly unusual for adults to run fevers with the early onset of a typical cold, but it might happen.  It is not uncommon at all for a young child to run a fever with the early onset of a cold.

The first three days of a "typical" cold are usually the worst.  The sore throat, the occasional coughing, the increasing nasal congestion, runny nose and feeling "blah."  Usually by day four, the sore throat is going away and the nasal congestion becomes the most significant symptom.  The nasal congestion can drag on for several days, getting slowly better.  But usually at this stage energy is returning, and the malaise and feeling grungy are going away.  Most people with a cold will be able to tell they are getting better day by day after the first week.  It may take them another week or even two to get "back to normal" but at least they can tell they're getting better. 

Depending on the strain of virus and the individual make up of the patient, symptoms may descend into the chest.  It is NOT uncommon for colds to cause some chest congestion, a moderate cough which is sometimes productive of some mucus, and sometimes a dramatic cough frequency and severity.  The cough can sometimes interfere with sleep. 

The following is a list of symptoms that typical colds should NOT cause:

--persistent high fevers over 101.5 (more than 1-2 days)

--nausea and vomiting

--severe headaches

--shortness of breath (other than perhaps during a coughing spell)

--persistent unilateral ear pain

--a sore throat so bad it is hard to swallow food or liquids

--persistent (over 3 days) of continuous one-sided severe sinus or facial pressure pain that does not respond to over-the-counter symptom relievers

Management of a cold: 

Since a cold is caused by a virus, there is really not much you can do to rid yourself of a cold once it takes hold. 

The best recommendations are to stay home for the first two days, rest, stay well hydrated, and treat your symptoms if they bother you a lot. 

Zinc and colds:  There is some good evidence that taking zinc (typically in the form of zinc lozenges) at the earliest signs of a cold can reduce the severity and duration of a cold.  However, the study that came to this conclusion cautioned that more research needs to be done in terms of zinc dosing specifics.  Zinc is not without side effects:  many people using zinc lozenges in the frequency recommended to shorten colds experience a funky, metallic taste from the zinc, and can experience nausea and headaches.
 
See the link:
http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD001364.pub3/abstract;jsessionid=5319A4F7F16131B89882E4A3DBEAAD4C.d03t04

Vitamin C and colds:  This has been a moderately debated issue for the past six decades.  Recently a meta-analysis of studies of vitamin C and colds concluded that taking vitamin C in high doses (2000 to 3000 mg) a day at the onset of a cold does NOT shorten or lessen the severity of a cold.  However, in people who take high doses of vitamin C on a regular, daily basis, there was a slight but statistically significant reduction in the frequency and severity of colds. 

Airborne and Colds:  Don't even get me started on this one.  NO evidence whatsoever exists that Airborne can do anything to prevent or shorten colds.  The company was actually fined for making false claims, however, the FDA allowed them to continue to market the product (why is beyond me). 

For other symptoms of colds:

--for aches and pains and sore throat:  acetaminophen (tylenol) or ibuprofen or naproxen can help.  Don't use ibuprofen or naproxen if you have a significant history of stomach ulcers or bleeding, or if you have kidney disease. 

--for coughs:  dextromethorphan is the most potent over-the-counter cough suppressant.  It can be found in products like Robitussin DM or Mucinex DM (the DM is for dextromethorphan).  Usually (as in these named products) the dextromethorphan is combined with guaifenesin, which is allegedly a mucus loosener/thinner.  Actually lemon and honey is a very good cough remedy.  Of course, cough drops or throat lozenges can help reduce the coughs that come from the scratchy throat. 

Nighttime coughs that result from an insistently tickly throat are often due to post-nasal drainage.  I describe these coughs as though someone is pricking the back of my throat with pins and needles.  The best options for these types of coughs are throat lozenges that sort of numb the area, or throat sprays like Chloraseptic, or decongestant nasal sprays like Afrin.  There is a particular prescription medication in the form of a nasal spray called ipratropium (Atrovent is the trade name) nasal spray that can dramatically reduce post-nasal drippage and prevent these nighttime coughing spells. 

For the nasal congestion, there are three options: 
--nasal saline sprays and rinses (like the NeilMed nasal saline rinse kits or "Neti-Pots").  These, of course, are very safe, and can be used as often as needed. 

--Nasal spray decongestants such as Afrin.  These can work pretty well, but have a "dark side" to them.  If used regularly for more than about one week, your nasal linings can get "addicted" to them.  Then when you try to stop using them, you nasal mucus membranes get all swollen and congested because they've literally gotten used to having the Afrin there to shrink up the swollen blood vessels.  So I always warn my patients that if they use OTC nasal spray decongestants, the MUST stop after one week. 

--Oral "pill" form decongestants.  There are only two over-the-counter medications that can act as decongestants.  Pseudoephedrine (SOO-doh-uh-FED-rin), and phenylephrine (FEN-uhl-EFF-run).  Phenylephrine is found in OTC cold preparations and in Sudafed-PE.  You can buy these without any limitation.  Pseudoephedrine products like Mucinex D and Sudafed have to be signed for at the pharmacy counter.  This is because pseudoephedrine is a necessary ingredient in the manufacture of meth.  Oral decongestants can cause side effects other than elevated blood pressure:  rapid heart rate, palpitations, headache, insomnia, tremors, and irritability. 

People with high blood pressure, history of heart attacks, or history of strokes should NEVER use products with pseudoephedrine or phenylephrine, as these medications act like adrenaline and can dramatically elevate blood pressure. 

What do I do when I get a cold?  I stay home from work for at least the first two days, because that is when I am most infectious.  I try to really rest, hydrate, and will use an analgesic of some sort.  I might use Mucinex D during the day if I'm really bothered by nasal congestion.  At night I usually will use some Afrin (because it won't keep me awake), and later in the cold when I am usually bothered by nighttime post-nasal drainage, I'll use prescription ipratropium nasal spray to reduce the night coughing tendency.  I wash my hands even more than I usually do. 

Preventing the spread of colds:  Cold virus incubation time is about one week.  Cold viruses are spread by touch--that is, if someone has a cold, the virus is in the mucus and secretions of the nose and eyes and throat.  If they touch those secretions and then touch a surface, and then you come along and touch that same surface and then touch your eyes, nose, or mouth--then you've just transmitted the virus to yourself.  Maybe your immune system will take care of it and nothing will happen.  But if you are stressed, not sleeping well, not eating well, or otherwise have side-tracked your immune system, then usually within a few days to a week you'll be getting that familiar back-of-the throat feeling that tells you you're catching a cold.   

A few myths about colds: 

--discolored nasal drainage means you have a bacterial sinus infection.  Discolored nasal drainage does not really mean much.  We'll discuss the differentiation between sinus infections and colds shortly.

--Being in drafts or cold weather can make you get a cold.  Being exposed to cold weather stresses your immune system which can make you less likely to fend off a cold if you are exposed.  But drafts or cold air do not, in and of themselves, cause colds.

--Drinking milk or dairy products makes mucus thicker.  Now this is an interesting issue.  I have NEVER seen any scientific investigation into this claim.  I should send this to "Myth Busters."  My wife works in the Music Theatre department at a local college and I have known many vocal performance majors and professional singers.  They all swear by this.  I'll just say I won't necessarily doubt thousands of singers out there, but I would sure like some kind of proof that isn't subject to the placebo effect. 

Influenza: 
Influenza can be considered a "cold on steroids."  When influenza hits, it hits HARD.  When someone comes down with the flu, they can run a fever for a couple of days, up to 102 or rarely even 103.  They will usually "hurt all over" with muscle aches and pains.  They usually don't want to move.  Flu symptoms are more "systemic" as opposed to a cold.  People feel bad all over their bodies.  They may get chills, sweats, and severe fatigue.  They will quite frequently have a headache.  They might develop some nausea and possibly diarrhea and rarely vomiting. 

HOWEVER, when medical people say "the flu" they do NOT mean an illness characterized by nausea, vomiting, diarrhea and abdominal cramping that can last for 1-3 days.  I run into this common misperception regularly.  Or people will refer to the "stomach flu."  I really have no idea why this labeling of a gastrointestinal illness as a "flu" got started.  But I digress. . .

Back to influenza:  The general systemic sense of illness with influenza can last several days.  There is also usually a mildly productive, harsh, sometimes painful cough, and mild to moderate nasal congestion than can last for 2 weeks or longer.  Everything with the flu takes longer than with a cold.  People are usually making progress after 7-10 days, but it is very slow.  The fatigue can go on for 3-5 weeks.  The cough can linger for 4-6 weeks. 

In short, influenza differs from a cold by the following:

--General whole body misery, aches, pains
--headache
--fever for 1-3 days is not uncommon
--severe fatigue

Prevention of influenza: 
The flu vaccine:

Large scale studies of influenza vaccine effectiveness shows that it runs around 60-80% effective in reducing the likelihood of getting the flu for persons over age 2 and under age 65. 

Studies show that the vaccine is less effective in kids under 2 and in adults over 65, for various reasons. However, it is still worth considering as side effects or complications of the vaccine are extremely rare, and it can reduce the risk of getting the flu, even if only modestly.

Common flu vaccine myth:  Getting a flu shot vaccine can give you the flu.  This is absolutely false.  The injectable vaccine cannot cause influenza.  It is an inactivated, killed virus.  The nasal spray FluMist vaccine potentially can cause influenza, as it is a "live, attenuated virus vaccine."  But that very rarely happens. 
 
Influenza is spread more by aerosol droplets from people coughing and sneezing as opposed to the contact-type transmission of colds.  So having people with the flu stay home from work for the 4-5 days they are most infectious is a great idea.  If they are out and about, they should wear masks. 

If someone is necessarily exposed to a person with the flu, that someone can be started on a preventive dose of Tamiflu (oseltamavir), which is an anti-viral drug designed to reduce infection from influenza.  It is not a guarantee, but it is the only preventive known other than avoidance and the flu vaccine.  The preventive dose of Tamiflu is 75 mg once a day for the duration of exposure. 

Treatment of Influenza: 
Basically the management of influenza is the same as the management of a cold:  Symptom relievers.  Bed rest, lots of fluids for hydration, analgesics for the body aches and pains as well as fever reduction.  Over-the-counter cough medication, throat lozenges, over-the-counter decongestants as needed.  Sometimes, prescription cough medications need to be used if the cough is severe and persistently keeping the patient awake.  It is hard to recover if you are constantly sleep deprived. 

If a patient strongly suspects they have influenza, there is a rapid test that can be done by passing a small swab back into the nose all the way to the back of the throat.  It can tell us if the patient has influenza, and if we know we are seeing the patient in the first 48 hours of the process, we can start the patient on Tamiflu 75 mg twice a day for 5 days to try to reduce the duration and frequency of the illness.  I don't always feel the necessity of doing the rapid test--there are times when a patient's history and presentation and physical exam suggest influenza, and if everything fits, I'll write a prescription for Tamiflu without a rapid test. 

The main thing to remember with influenza is that it can last 2 weeks and then the residual cough, mild congestion, and significant fatigue can drag on for 2-3 weeks more. 

Sinus Infections:

Trying to determine who has a bacterial sinus infection versus who just has a bad cold is one of the most common frustrations of primary care.  Bacterial sinus infections can rarely occur as a complication of a cold.  Bacterial sinus infections almost NEVER occur spontaneously, out-of-the-blue, without some type of initial process that closes off the sinus openings. 

The heart of the issue is that several well-designed studies have shown that about 85% of antibiotics used to treat presumed bacterial sinus infections are absolutely unnecessary.  Using antibiotics unnecessarily increases the general risk of bacterial resistance to antibiotics, and we have a huge problem with that as it is. 


Bacterial sinus infections evolve during a bad cold in the following way:  A cold causes inflammation and swelling of the nasal mucus membranes.  It also causes an increase in mucus secretions by the mucus membranes.  The sinuses are best thought of as sort of "caves" buried in the facial bones on either side of the nose and above the eyebrows, and in the skull bones behind the nose.  These are more accurately called the "paranasal" sinuses, because there are many other "sinuses" in the human body. 

The sinus caves in the facial bones (maxillary sinuses in the cheekbones, frontal sinuses in the forehead, ethmoid and sphenoid sinuses behind the nose and eyes) are lined with mucus-secreting membranes.  They also are lined with small cells which have cilia--microscopic whip-like projections that constantly beat and whip that mucus up and out of the sinus, through a small opening into the nasal passages called an ostium. 

During a cold, the mucus membranes of the nasal passages can get so swollen that the openings to the sinuses (the ostia) get blocked.  So the mucus secreted inside the sinuses can't get out.  Also, with the openings blocked, changes in atmospheric pressure cannot be equalized, and can cause temporary pressure pain in the sinuses.  So we have blocked sinus openings, increasing mucus build up, and inadequate pressure equalization.  But these are just what can happen with a regular cold. 

A bacterial sinus infection develops when the germs/bacteria that live in the nose and throat make their way into the sinuses, and find a nice, secluded, warm, soupy mucousy mess which is a perfect growth medium for them.  Since the normal "cleansing" mechanism of the sinuses is not working (the sweeping of the mucus by the cilia out of the sinus ostia), the germs can grab a foothold and start to reproduce.  When that happens, white blood cell police get called to the bad-boy germ party now out of control.  A pitched battle ensues.  White blood cells fight the bacteria, and many of them die in the war.  The decaying white blood cells and bacteria cause pus, which adds to the mucus AND adds to the inflammatory reaction in the sinuses, further aggravating swelling and pressure, and perhaps even causing a low-grade fever and malaise and fatigue. 

How do we know if you have a sinus infection and not just a cold?  

--sinus infections typically come at the tail-end of a cold, often after you have already started getting better.  So we look for what is called "double-sickening"--that is, a cold starts, then starts going away, then you get worse again with sinus pressure symptoms, fatigue, and perhaps worsening mucus secretion. 

--sinus infections typically are associated with persistent sinus pressure pain, and often even tenderness over them.  Some people complain of pain in their upper teeth when the maxillary sinuses are involved.  

--sinus infections are often associated with a definite systemic sense of illness.  Fatigue, chills, feeling yucky.  

We have definite history questions that help us decide the likelihood that a patient has a true sinus infection.  The first question I ask is, "How long have you been ill?"  If the answer is four days, I am not thinking this patient has a sinus infection.  It is incredibly unusual for a bacterial sinus infection to take hold and flourish in only four days.  If they say, "Two and a half weeks," then I'm much more suspicious of a true bacterial sinus infection. 

The other questions I'll ask relate to the "double-sickening" mentioned above.  Then I ask if there is persistent sinus pressure pain for more than just a couple of days. 

Signs and symptoms I want to see prior to starting antibiotic treatment for a sinus infection:

--Upper respiratory symptoms that have gone on for over 7-10 days. 

--A pattern of initial improvement followed by worsening illness, especially after an initial week of symptoms. 

--persistent sinus pressure pain AND tenderness.

--Systemic symptoms of malaise, low grade fever, fatigue.  

During the physical exam, I would like to see demonstrable sinus tenderness to pressure from my fingers, puffiness around the eyes, significant nasal mucosal swelling and inflammation, discolored post-nasal drainage down the back of the throat, foul breath (well, I'm not looking forward to that, necessarily), and a particular change in the voice quality of the patient characterized by a loss of facial bone resonance (any professional singer will tell you that open sinuses affect the timbre and resonance of the voice--thus if sinuses are filled or not open, the voice quality changes). 


Treatment of Bacterial Sinus Infections: 
Mainstays of treatment are:
--antibiotics to cover the most common bacterial causes of sinus infections.  Commonly used antibiotics are azithromycin, amoxicillin or amoxicillin-clavulanate, cephalosporins such as cephalexin or cefuroxime, sulfa antibiotics such as Bactrim DS or Septra DS, or sometimes levaquin. 

--decongestants:  to try to open up the swollen, congested nasal mucus membranes.

--corticosteroids:  It is not uncommon that we might use a course of oral prednisone to try to reduce the inflammatory swelling of the nasal mucus membranes.  There is no strong evidence data to back up this practice, however.

See the Cochrane Review link:

    http://summaries.cochrane.org/CD008115/systemic-corticosteroids-for-acute-sinusitis

Sometimes we might start a patient on a nasal spray corticosteroid such as fluticasone (Flonase), but nasal spray steroids take a good 5-8 days to have any effect at all. 

--Nasal saline rinses like NeilMed nasal rinse or a Neti-pot.

--Hydration to help thin out mucus secretions. 

--analgesics such as tylenol or ibuprofen or naproxen for pain/pressure relief. 

Once treatment has started, it may take 7-10 days to make headway on symptoms.  I usually expect to at least see improvement by 4-5 days, and expect the patient to be close to "back to normal" by 2-3 weeks. 

If a patient has an excellent history for a true bacterial sinus infection and is not getting better on maximal therapy after 7-10 days, I may change antibiotics to something different, assuming perhaps the germ is resistant to the originally-selected antibiotic. 

If the patient STILL is making no progress after a second course of oral antibiotics, then I'm suspicious we are not dealing with a typical bacterial sinus infection.  If this occurs, I will set the patient up for a CT scan of their sinuses to see if something is amiss with their anatomy and to confirm if we are really dealing with a true sinusitis.  Depending on the outcome of the CT, I may then refer the patient to an Ear/Nose/Throat specialist.  (The CT scan below shows the maxillary sinus on the right side of the photo filled with fluid, indicating an acute sinus infection.) 

Frustration Note: 
It drives me crazy when a patient is seen in another setting by another provider for 4 days of cold symptoms.  They get started on antibiotics by a well-meaning but hurried provider for a presumed "sinus infection."  (This often happens because it is quicker and simpler to hand someone a prescription than it is to educate them in the differences between viral colds and bacterial sinus infections.) Then in 3-4 days the patient calls me saying their antibiotic is not working and they are still having symptoms.  At that point I am in a quandary--are they not better because they just have a cold virus and antibiotics do nothing against viruses?  Or do they truly have a bacterial sinus infection that is resistant to the antibiotic chosen, and I need to change antibiotics?  If it seems fairly obvious that they were simply treated too early, I'll ask them to wait at least a few more days to see if the symptoms start to subside, as they should with a viral cold. 

Strep Throat:

Strep throat is seen more often in children and adolescents than adults, but we still see it in adults frequently enough. 

Symptoms of strep throat are a persistent sore throat, maybe even severe.  There may be difficulty swallowing.  There can be fever (more likely in children).  There is often swelling of the lymph nodes at the top of the neck beneath the angle of the jawbone.  There can be general fatigue an malaise. 

Strep throat typically is NOT associated with:
--significant nasal congestion and drainage
--cough, although an occasional nonproductive cough just from throat irritation may occur. 

The physical exam is often very telling in strep throat: the back of the throat tends to be "beefy" red.  If tonsils are present they are often very swollen.  There may be even some whitish "exudate" on the tonsils or throat.  The voice has an odd obstructed quality to it. 

We often will do a rapid strep screen throat swab test if we're suspicious.  However, if I have a history that sounds pretty typical and typical physical exam findings, I'll just treat the patient directly rather than doing a throat swab test. 

The throat swab test is pretty accurate (if done correctly), but does have some degree of a false negative rate.  If I'm highly suspicious, but the rapid test comes back negative, I may treat the patient for presumed strep but run a confirmatory "throat culture" in which the actual germs from the throat are grown in an incubator for 2-3 days and then we can determine much more certainly if the patient does or does not have strep. 

Strep fortunately continues to be pretty easy to treat.  It responds typically in 48 hours to simple antibiotics like amoxicillin.  However, strep throat is the one respiratory infection that I warn patients to absolutely complete the full ten day course of antibiotics even if they have felt "back to normal" for several days.  Inadequately or incompletely treated strep can in rare cases lead to strep germs making their way into the kidneys or onto the heart valve leaflets, causing serious kidney or heart valve infections. 

Still to go:  Ear infections, then lower respiratory tract infections such as bronchitis and pneumonia.  Work in progress...