Infections of the Upper Airway- Common Cold and Sinusitis

COMMON COLD 

• Also known as viral rhinitis, viral rhinosinusitis, acute rhinosinusitis or acute rhinopharyngitis . Children have 6 to 8 episodes of the common cold per year.  2 to 3 episodes per year in adults.  Increased frequency of common cold is seen in Mannose-binding lectin deficiency (5-30%).

ETIOLOGY 

• The most common virus causing the common cold is Rhinovirus. Others are Parainfluenza virus, Influenza virus, Respiratory syncytial virus, Human metapneumovirus, Coronavirus and Adenovirus

Why is this upper airway infection so common?

• Many serotypes present -If a person gets infected by the parainfluenza virus, the antibodies formed against this will not protect the body against another. Each time there is a new serotype, the body's immune response may not be able to fight against it. Response in the form of IgA mediated. It is found IgA mediated response is short-lived.

Clinical Features of Upper Airway Infection

Modes of transmission of upper airway  infections 

• Direct hand contact- hand hygiene is implicated. When a person sneezes, the droplets are on the surface when anyone touches them, and that surface and hand are in direct body contact.
• Small droplet aerosol - small droplets suspended in the air for at least 5 to 10 mins which a person inhales, and aerosols.
• Large droplet aerosol - large droplets are not suspended in the air, but somebody sneezes standing very close, and the aerosols are inhaled.

There is a lag period of 1 to 3 days in which the child develops

• Nasal symptoms like nasal block and rhinorrhoea, initially watery later become purulent. The mucus's colour and consistency do not indicate starting any kind of antibiotics or any secondary treatment. Cough -Dry or can be purulent, seen in ⅔ cases. Fever may or may not be present.

Ear pain, Lymphadenopathy Malaise, sore throat, and irritability are the other symptoms.

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Diagnosis of Upper Airway Infection

• Clinical diagnosis and PCR -it identifies the specific virus. 

Treatment of Upper Airway Infection

• Supportive. No role of antibiotics/cough syrup/desi remedies. In fever, paracetamol is given 15mg/kg/dose, can be repeated every 4 to 6 hours if needed. In dry cough, severe nocturnal cough, and if it is causing sleep disturbance, 1-2 tablespoon of honey is given at or above 1 year of age by dissolving in warm water. In dry cough associated with significant nasal discharge, low-dose H1 antihistamines (SOS) given above 6 years of age.  Side effect - sedation and hyperactivity. Oral zinc lozenges are given above 6 years of age. Zinc inhibits in vitro 3C protease enzyme of rhinovirus. Decreased duration but no effect on severity.  Phenylephrine, Dextromethorphan, and Guaifenesin are not recommended.  Vitamin C is not recommended for the treatment of the common cold. Role of the nasal spray: A nasal spray containing saline used as SOS for blocked noses. Sprays containing xylometazoline are avoided.

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Prevention of Upper Airway Infection

• Hand hygiene: Vitamin C is used in the prevention, not in the treatment of disease. Zinc used in the treatment of disease. If vitamin C starts within 24 hours at the onset of the upper airway infection or before exposure, it decreases the duration of the disease and not the severity.

Complications of Upper Airway Infection

• Acute otitis media. (5-30%), acute sinusitis and asthma exacerbation 

DEVELOPMENT OF PARANASAL SINUS 

• Ethmoidal: It is well developed and present at birth. Maxillary- It is present at birth but not pneumatized and gets pneumatized at 4 years of age. Sphenoidal-It develops and pneumatized at 5 years of age. More than 3 months. Frontal-Appears at 7-8 years but well developed and pneumatized till late adolescents or adulthood.

SINUSITIS IN CHILDREN 

• Sinusitis is defined as acute when it lasts less than 1 month. Subacute when it last for 1 to 3 months. Chronic when it lasts more than 3 months. Sinusitis, in most cases, arises as a complication of pre-existing viral infection. Sometimes it is De novo. Etiology – Mostly bacterial. Fungal sinusitis can be immunocompromised. 

3 causes of acute sinusitis are:

• S. pneumoniae (30%) - positive for penicillin resistance.
• H. Influenza (30%) -positive for beta- lactamase.
• M.Catarrhalis (10%)- positive for beta- lactamase.

• Other causes of chronic and subacute sinusitis are H. Influenza, M.Catarrhalis , S. pneumoniae , Alpha and beta-hemolytic streptococcus , CONS, S .aureus

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EPIDEMIOLOGY AND RISK FACTORS 

• It can occur in people of any age group. Risk of Complication more with:  

black ethnicity, Males > Females.

Risk factors 

• Viral rhinitis, allergic rhinitis, exposure to tobacco smoke – Passive smoking, Cystic Fibrosis, prolonged nasopharyngeal intubation , Immunodeficiency , prolonged steroid therapy. Clinical diagnosis of sinusitis - 2 major or 1 major + 2 minor symptoms. Symptoms like facial congestion or fullness, facial pain or pressure, hyposmia, or anosmia are more common in older children and adults.

APPROACH 

• Clinical diagnostic criteria can be used for diagnosis. Additionally, when to suspect sinusitis in a pre-existing cold. Persistent symptoms for more than 10 days. Severe symptoms for more than 3 days. Worsening or double sickening. This is a condition when a patient's condition gets worse after healing. 

INVESTIGATIONS 

• Sinus aspirate culture- gives maximum yield for culture. Done in immunocompromised, patient with severe symptoms or complications. Rigid nasal endoscopy.  Radiology - X-ray , CT scan. The x-ray and CT scan findings - opacification, air-fluid levels, etc.

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MANAGEMENT PROTOCOL 

• If there is no risk of resistance, then first-line microbial therapy is started.  In case there is a risk of resistance ,2-line microbial therapy is started. In the first line of antimicrobial therapy, Oral therapy of amoxicillin + clav (40-50 mg/kg/day.). It is given for 5 to 7 days. In second-line microbial therapy , Amoxicillin dose is increased to   80-90 mg/kg/day. It is given for 7-10 days.
• Alternative agents: Oral levofloxacin (10-20mg/kg/day), Oral cefixime (10-20 mg/kg/day), IV/IM ceftriaxone . If the condition worsens after 3 to 5 days MRI OR CT SCAN is performed to give the diagnosis. In general, antibiotic therapy is given for 10 days. Azithromycin and cotrimoxazole are no longer indicated because of a high prevalence of antibiotic resistance in sinusitis. Therapy with antimicrobials is given for at least 10 days or 7 days after the resolution of symptoms. Decongestants, antihistamines, mucolytics, and intranasal corticosteroids are not recommended for the treatment of acute uncomplicated bacterial sinusitis in children. There are 50 to 70% of these can cure without antibiotics, but there are even high chances that the situation may get worse.

COMPLICATIONS 

• Orbital cellulitis present as swelling, proptosis, chemosis, and visual disturbances. Osteomyelitis of frontal bone: Pott's puffy tumour.  Mucocele in the frontal sinus displaces the eyeball and causes Diplopia.

Intracranial complications: Cavernous sinus thrombosis, Meningitis, Subdural empyema, Epidural abscess, Brain abscess.  Common symptoms like: - Altered sensorium, depressed sensorium, decreased GCS. Raised intracranial pressure.  Severe headache and May or may not be seizures. In complication, parenteral antibiotics - IV ceftriaxone (50-100mg/kg/day) given.

HOT SNIPPET 

• In frontal sinusitis, lead to osteomyelitis of the frontal bone. Frontal bone will cause dissemination of the bacteria, its accumulation in the subperiosteal area, causing subperiosteal extracranial abscess, seen on forehead.  The abscess can also shifts posteriorly and compresses the brain causing a paramedical extra cerebral abscess. To detect the Pott's puffy tumour- CT scan is done.  IV antibiotics are started.  Surgical drainage of the abscess- Endonasal approach and Open surgical approach

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Hope you found this blog helpful for your NEET SS General Pediatrics preparation. For more informative and interesting posts like these, keep reading PrepLadder’s blogs.