Upper respiratory tract infections: Clinical sciences

Chapters:

Watch video only

Introduction0:00–0:28

Upper respiratory tract infections, or URIs, are a common cause of acute illness. They occur when a pathogen causes inflammation in the nasal cavity, sinuses, and throat.
Based on their clinical presentation, URIs can be classified as; pharyngitis; acute rhinosinusitis, also known as acute sinusitis; and unspecified URI.Now, if you suspect a URI, you first should perform an ABCDE assessment to determine if the patient is unstable or stable.

Unstable patient0:28–1:37

If they are unstable, stabilize their airway, breathing, and circulation. Next, obtain IV access, provide supplemental oxygen, and put them on continuous vital sign monitoring, including blood pressure, heart rate, and pulse oximetry.
Finally, don’t forget to start IV empiric broad-spectrum antibiotics.Now, here’s a high-yield fact! If your patient presents with drooling, tender neck swelling, and inspiratory stridor, along with painful and difficult swallowing, you should suspect epiglottitis or retropharyngeal abscess.
These conditions can be caused by Streptococcus pneumoniae or pyogenes, as well as Staphylococcus aureus, and can quickly lead to airway compromise.
Also consider Lemierre syndrome, which is septic thrombophlebitis of the internal jugular vein and is caused by the anaerobe Fusobacterium necrophorum.
Okay, now that we’ve dealt with unstable patients, let’s return to the ABCDE assessment and focus on stable patients. If your patient is stable, proceed with obtaining a focused history and physical exam.

Stable patient1:37–2:39

The history will commonly reveal symptoms of fatigue, runny nose, and fever. Additionally, the patient might report a sore throat, as well as cough.
The general physical exam will reveal an ill-appearing person. At this point, you should suspect a URI, so your next step is to classify it clinically as pharyngitis, acute rhinosinusitis, or unspecified URI.Here’s a clinical pearl!
Don’t forget to inquire about a history of allergies, lung disorders, immunosuppression, tobacco use, recent sick contacts, and recent travel history, as these may change not only what pathogens you think are involved, but also the severity of the disease.

Pharyngitis2:39–6:51

Okay, first let’s discuss an individual that has primarily a sore throat. They may also report rigors, night sweats, painful swallowing, or a cough.
The physical exam could reveal enlarged tender cervical lymph nodes, a scarlatiniform rash, palatal petechiae, swollen tonsils, and tonsillopharyngeal exudates.
Based on these findings, you can diagnose pharyngitis. Next, you need to assess for Group A Strep using the Centor Criteria, which assigns 1 point to each clinical finding.
These findings include the absence of a cough; a fever equal or greater than 38oC or 100.4oF; tender anterior cervical lymphadenopathy; and tonsillar exudates or swelling.
Lastly, an additional point is added if the patient is between 3 and 14 years of age since GAS is incredibly rare in patients under 3, and less common in older adults.Here’s a high-yield fact!
EBV-induced infectious mononucleosis should be suspected when an adolescent or young adult complains of sore throat, fever, and malaise, and also has lymphadenopathy and pharyngitis on physical examination.First, if your patient has 1 or no points, then no further testing is recommended.
Diagnose this as viral pharyngitis and provide symptomatic treatment with analgesics and antipyretics like acetaminophen or nonsteroidal anti-inflammatory drugs.
Additionally, throat lozenges, salt water gargles, or viscous lidocaine might be helpful. Lastly, provide reassurance that this will resolve on its own and that antibiotics are not necessary.
Now, if your patient has 2 or 3 points, you should perform a rapid strep antigen test. If this is negative, diagnose the patient with unspecified pharyngitis, and provide symptomatic treatment.
In the meantime, the swab from the rapid strep antigen test should be sent for Group A Strep culture, which might take a few days.
If the culture comes back negative, this confirms the diagnosis of unspecified pharyngitis and you should continue symptomatic treatment.
On the other hand, if the culture is positive, then refine your diagnosis to Group A Strep Pharyngitis, and continue with symptomatic treatment and add antibiotics, such as a beta-lactam penicillin, like amoxicillin.
If the individual has a penicillin allergy, then consider a macrolide, like azithromycin. This will treat the throat infection and will prevent complications such as abscesses or rheumatic fever.Okay, let’s go back to the initial rapid strep antigen test.
Now, if this test is positive, then diagnose Group A Strep Pharyngitis and treat it symptomatically and with beta-lactam penicillin, primarily amoxicillin.Lastly, if your patient meets 4 or more points, no additional testing is needed and you can clinically diagnose Group A Strep Pharyngitis.
Again, treatment consists of symptom management and amoxicillin. Timely diagnosis and treatment of group A strep is important because this infection can have long-lasting consequences, including rheumatic feve.
Now here’s a high yield fact! Poststreptococcal glomerulonephritis can develop despite treating an acute group A strep infection.
If this happens, it’s usually 1 to 2 weeks after the group A strep throat infection; and it has features of the nephritic syndrome, such as hematuria, oliguria, hypertension, and edema; though keep in mind that it can also present with significant proteinuria.Now, let’s go back and discuss an individual that reports nasal congestion and decreased or absent sense of smell.

Acute Rhinosinusitis6:51–9:38

There could also be upper teeth pain, facial pain or pressure, and earache, as well as cough and headache. Additionally, their physical exam may reveal tenderness to palpation over the sinuses, halitosis, and possible purulent nasal discharge and bulging tympanic membranes.
With these findings, you should diagnose acute rhinosinusitis. Next, assess the severity of their presentation to help determine whether this is a viral or bacterial infection.
There are three presentations that should make you think of a bacterial infection. The first is a severe onset of symptoms, which means a high fever greater than 39oC or 102.2oF plus purulent nasal discharge or facial pain for at least 3 days.
The second presentation includes a patient with persistent symptoms without improvement for 10 or more days. Lastly, is double sickening, which means the patient reports mild symptoms that initially improved, but then acutely worsened again without other explanation.
Now, if any of these are present, diagnose Bacterial Rhinosinusitis, which is most commonly caused by Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis.
Management includes symptomatic treatment and antibiotics, typically with a beta-lactam penicillin, like amoxicillin-clavulanate.
If your patient has a penicillin allergy, then consider the tetracycline antibiotic doxycycline. Keep in mind that acute bacterial rhinosinusitis is associated with complications like otitis media, meningitis, osteomyelitis, and abscesses.Now, here’s a clinical pearl!
If your patient is immunocompromised and you’re concerned about rhinosinusitis, don’t forget to consider invasive fungal sinusitis caused by mucormycosis.Now, let’s go back to assessing for severity.
If no signs of severity are present, diagnose viral rhinosinusitis and treat symptomatically with analgesics, antipyretics, and intranasal saline irrigation or intranasal corticosteroids.
You can also offer systemic or topical decongestants, mucolytics, or antihistamines. Once again, you should provide reassurance that antibiotics are not required and that symptoms will resolve with time.Finally, let's go back and discuss an individual that reports symptoms of nasal congestion, sneezing, and headache.

Unspecified URI9:38–12:20

Other common symptoms include muscle aches, hoarseness, diarrhea, or decreased or absent sense of smell. Physical exam will commonly reveal clear nasal discharge, as well as mouth ulcers, also known as aphthous ulcers or canker sores.
In this case, diagnose an Unspecified URI and perform a rapid influenza and SARS-CoV-2 swabs.Now, let’s look at our rapid viral swab results.
If both of these swabs come back negative, then you can diagnose a viral URI, also called the common cold, which is typically caused by rhinovirus.
Other causes include coronavirus, respiratory syncytial virus, and adenovirus. Treatment includes reassurance that antibiotics are not required and that symptoms should resolve on their own.
Additionally, symptomatic treatment with analgesics, antipyretics, decongestants, and antihistamines may provide some relief.
Lastly, counsel your patient on prevention, such as proper handwashing and the need to follow-up if they’re worsening or not improving after 2 weeks.
Okay, now let’s go back to our rapid viral swabs. If the influenza swab comes back positive, then diagnose Influenza.
Treatment includes reassurance that antibiotics are not indicated. Additionally, if your patient’s symptoms started less than 48 hours ago, you may consider prescribing the antiviral neuraminidase inhibitor, oseltamivir.
Management consists of symptomatic treatment, as well as counseling on prevention with proper handwashing and yearly influenza vaccination, and follow-up if their symptoms are worsening or not improving.Finally, if the rapid viral swab is positive for SARS-CoV-2, then diagnose your patient with COVID-19 infection.
In this case, treatment includes reassurance that antibiotics are not indicated, while monoclonal antibodies or the antivirals, such as nirmatrelvir and ritonavir, might help non-severe infection in certain high-risk populations.
Also, don’t forget symptomatic treatment, as well as counseling on prevention with proper handwashing and COVID-19 vaccination, and follow-up if they’re worsening or not improving.Alright, as a quick recap… If you suspect a URI, first perform an ABCDE assessment.
If unstable, stabilize the patient and begin empiric broad spectrum IV antibiotics. If your patient is stable, classify them based on predominant clinical findings.
If you diagnose pharyngitis, use the Centor Criteria to differentiate Group A Strep from other causes. Treat viral and unspecified pharyngitis symptomatically, and Streptococcal pharyngitis with amoxicillin.

Review12:20–13:46

In acute rhinosinusitis, if there’s evidence of severe disease, diagnose bacterial rhinosinusitis and start amoxicillin clavulanate.
If there’s no evidence of severe disease, consider viral rhinosinusitis and treat symptomatically. Lastly, in an unspecified URI, order influenza and SARS-CoV-2 swab to differentiate the common cold from influenza and COVID-19.
All unspecified URIs should receive symptomatic treatment, education on prevention and follow-up. Individuals with influenza or COVID-19 might benefit from anti-viral therapy and should receive yearly vaccination and follow-up.
I order influenza and SARS COVID two swab to differentiate the common cold from influenza and COVID-19 all unspecified should receive symptomatic treatment education on prevention and follow-up Individuals with influenza or COVID-19 might benefit from antiviral therapy and should receive yearly