Anatomy and terminology of the upper respiratory tract
Common cold is an infectious disease of the upper respiratory tract. The upper respiratory tract includes the sinuses, nasal cavity with tonsils, pharynx, and larynx. Below the larynx lie the lower respiratory tract structures: trachea, bronchi, and lung parenchyma (where, in particular, community-acquired pneumonia develops).
To denote inflammation of a specific structure, terms with the suffix "-itis" are used:
- Inflammation of the sinuses — sinusitis; inflammation of the nose — rhinitis; when both are affected simultaneously — rhinosinusitis.
- Inflammation of the pharynx is pharyngitis; in combination with rhinitis, it is nasopharyngitis.
- Inflammation of the tonsils is tonsillitis; in combination with pharyngitis, it is tonsillopharyngitis.
- Inflammation of the larynx is laryngitis.
The middle ear is connected to the nasopharynx via the Eustachian tube, which equalizes pressure on both sides of the tympanic membrane. Infection can spread in both directions through this channel, leading to secretory otitis media when drainage is impaired.
Symptoms by localization of the lesion
- Sinusitis: nasal congestion, a feeling of fullness and facial pain, nasal discharge.
- Rhinitis: abundant nasal discharge, including discharge trickling down the posterior pharyngeal wall—post-nasal drip, which accounts for a significant portion of cough following a viral infection.
- Pharyngitis: sore throat, scratchy throat, mucosal hyperemia.
- Tonsillitis: more intense pain upon swallowing, sometimes pain upon opening the mouth, regional lymphadenopathy (submandibular, anterior cervical lymph nodes).
- Laryngitis: cough, hoarseness due to vocal cord involvement. In children, a severe complication is possible—acute obstructive laryngitis, requiring emergency therapy with glucocorticosteroids.
History taking for cold complaints
In addition to the standard history of present illness, allergy and epidemiological history (contact with infectious patients), the following should be specifically clarified:
- presence of fullness or pain in the facial and frontal regions (signs of sinusitis);
- congestion and pain in the ears (signs of otitis media);
- sensation of mucus trickling down the posterior pharyngeal wall (post-nasal drip as a cause of cough);
- character of the cough: wet or dry, presence of blood in the sputum, predominant time of day, waking up at night from coughing;
- relationship of the cough to body position and food intake (possible link to gastroesophageal reflux disease and laryngopharyngeal reflux, which can cause chronic cough without heartburn);
- presence of chest pain and shortness of breath—red flag signs requiring an extended workup;
- maximum temperature and its dynamics, medications taken and their effectiveness.
Physical examination
A standard examination includes throat inspection, chest auscultation and percussion, and assessment of bronchophony. Additionally, maneuvers that physicians frequently neglect must be performed:
- palpation of sinus projection areas — tenderness is a significant sign of sinusitis;
- otoscopy — evaluation of the tympanic membrane for hyperemia and fluid in the middle ear;
- inspection of the hard palate and oropharynx with full visualization rather than a quick glance — detection of petechiae (hemorrhages), which point toward influenza or streptococcal pharyngitis;
- palpation of cervical, supraclavicular, and infraclavicular lymph nodes; in case of lymphadenopathy in more than one group — additional palpation of axillary lymph nodes and percussion/palpation of the spleen to rule out infectious mononucleosis.
Differential diagnosis of conditions mimicking a cold
About 80% of primary care visits are due to uncomplicated nasopharyngitis and laryngitis, which do not require specific therapy. However, the following must be ruled out:
- Bacterial sinusitis — biphasic course (improvement followed by secondary worsening) or symptom duration of more than 10 days.
- Streptococcal tonsillitis — assessed using the Centor criteria: absence of cough, tonsillar exudate, local lymphadenopathy, temperature above 38.3–38.5 °C. If two or more criteria are met, testing (rapid test, culture) is indicated, followed by a decision on antibiotic therapy.
- Bronchitis — cough, wheezing; in a protracted course lasting more than two weeks, Mycoplasma or Chlamydia etiology should be suspected and empirical therapy with macrolides considered.
- Influenza — pronounced systemic inflammatory syndrome (high fever, myalgia, headache) against the background of moderate respiratory symptoms, hemorrhagic syndrome (conjunctival vessel injection, hemorrhages on the hard palate). Diagnosis by PCR/antigen test is indicated for a limited group of patients (elderly, presentation within the first 72 hours when deciding on oseltamivir administration).
- Infectious mononucleosis — clinical presentation of tonsillitis combined with splenomegaly, hepatomegaly, generalized lymphadenopathy, and rash upon taking amoxicillin; diagnosis is made via blood smear and serology.
- Pertussis — paroxysmal cough leading to vomiting, unresponsive to standard therapy; diagnosis is made via PCR throat swab and culture.
Symptomatic treatment of the common cold
Specific prevention involves influenza vaccination. Treatment of an uncomplicated cold is symptom-based:
- Sore throat: lozenges, cold drinks and ice cream, gargling with salt and baking soda solution, topical NSAIDs (ketoprofen, benzydamine), and systemic NSAIDs.
- Runny nose and nasal congestion: saline flushes; vasoconstrictor drugs for no longer than 5 days due to the risk of medicamentosa rhinitis; intranasal ipratropium bromide for prominent rhinorrhea.
- Post-nasal drip with chronic cough: intranasal glucocorticosteroids (mometasone, fluticasone).
- Cough: lozenges and warm drinks in small sips, first-generation antihistamines, inhaled budesonide and ipratropium bromide for laryngitis or bronchitis.
- Fever: paracetamol, NSAIDs, physical cooling methods (sponging with room-temperature water relying on evaporation rather than cooling).
- In certain clinical situations, a single dose of systemic glucocorticosteroids (dexamethasone) may be used for rapid symptom relief, taking into account the risk of a protracted course.
Key points
- The common cold affects the upper respiratory tract: sinuses, nose, pharynx, tonsils, larynx.
- Post-nasal drip is a common and underestimated cause of cough after a viral infection.
- Centor criteria help determine the probability of streptococcal tonsillitis and the need for testing.
- Suspect bacterial sinusitis in case of a biphasic course or symptoms lasting longer than 10 days.
- Protracted bronchitis lasting more than 2 weeks requires considering a Mycoplasma etiology and macrolide therapy.
- Physical examination must include sinus palpation, otoscopy, and inspection of the hard palate, not just throat inspection.
- Cold treatment is symptomatic: from topical remedies to intranasal glucocorticosteroids for post-nasal drip.
- Vasoconstrictor drops are limited to 5 days of use due to the risk of rhinitis medicamentosa.