Otitis media

Acute Otitis Media (AOM)

typically follows a viral upper respiratory tract infection (URTI) that causes eustachian tube inflammation and dysfunction. Fluid accumulates in the middle ear, creating a breeding ground for bacteria.

The "Big Three" Pathogens

Streptococcus pneumoniae (Gram-positive diplococci)

Haemophilus influenzae (Gram-negative coccobacilli)

Moraxella catarrhalis (Gram-negative diplococci)

Note: Viruses cause up to 25% of cases, which is why antibiotics aren't always dispensed immediately.

Streptococcus pneumoniae (Gram-positive diplococci)

The most common cause. It is the least likely to resolve spontaneously and is known for altering its Penicillin-Binding Proteins (PBPs), requiring high-dose amoxicillin to overcome resistance.

Haemophilus influenzae (Gram-negative coccobacilli)

Often produces beta-lactamases (which destroy amoxicillin). If a patient has concurrent purulent conjunctivitis (pink eye) and AOM, it is almost always H. influenzae.

Moraxella catarrhalis (Gram-negative diplococci)

Almost 100% of strains produce beta-lactamases, but it usually causes milder disease and has a high rate of spontaneous resolution.

Signs/Symptom

Otalgia (ear pain, seen as ear tugging/rubbing in infants), fever, irritability, otorrhea (discharge if the eardrum ruptures).

Otoscopic Hallmarks

The defining diagnostic feature of AOM is a bulging tympanic membrane with absent or decreased mobility, often accompanied by erythema (redness) and a cloudy middle ear effusion.

The "Watchful Waiting" (Observation) Strategy

_{^{We do not always give antibiotics immediately in order to prevent resistance. Observation for 48–72 hours is recommended ONLY IF follow-up is assured, and the patient falls into these categories:}}

Children 6–23 months

Unilateral AOM without severe signs (mild pain, fever <39°C).

Children ≥ 2 years

Unilateral or Bilateral AOM without severe signs. (Rule of thumb: If the child is < 6 months old, or has severe symptoms like toxic appearance or high fever, ALWAYS prescribe antibiotics immediately).

First-Line Treatment

_{^{Amoxicillin is the definitive drug of choice.}}

• Dose: 80 to 90 mg/kg/day divided into 2 doses.

• Board Rationale: Why this specific high dose? It maximizes the concentration of the drug in the middle ear fluid to overwhelm the PBP-mediated resistance of S. pneumoniae.

When to use Amoxicillin-Clavulanate (Augmentin) First-Line?

Use Amox-Clav (90 mg/kg/day of the amoxicillin component) if the patient has:

1. Received amoxicillin in the past 30 days.

2. Concurrent purulent conjunctivitis (suspecting H. influenzae).

3. A history of recurrent AOM unresponsive to standard amoxicillin.

• Formulation Note: Use the 14:1 ratio formulation (e.g., ES-600 mg/42.9 mg per 5 mL) to minimize the clavulanate dose, which is notorious for causing severe diarrhea.

Non-Severe (Maculopapular Rash)

2nd/3rd Gen Cephalosporins: Cefdinir, Cefuroxime, Cefpodoxime, Ceftriaxone (IM/IV for vomiting patients).

Severe (Anaphylaxis/IgE-mediated)

Macrolides: Azithromycin or Clarithromycin. (Or Clindamycin, though it lacks H. influenzae coverage).

10 days

< 2 years old or severe symptoms

7 days

2 to 5 years old

5 to 7 days

≥ 6 years old

Pain Management (Analgesics)

_{^{Antibiotics take 24–48 hours to start providing clinical relief. You must recommend concurrent pain management:}}

• Acetaminophen (Paracetamol): 10-15 mg/kg/dose every 4–6 hours.

• Ibuprofen: 5-10 mg/kg/dose every 6–8 hours (only for children ≥ 6 months).

• Board Warning: NEVER recommend Aspirin for children with viral-like symptoms due to the fatal risk of Reye’s Syndrome (hepatic encephalopathy).

Reconstitution Instructions

_{^{For dry powder suspensions}}

Demonstrate how to tap the powder loose first. Add the required amount of purified water in two portions, shaking vigorously between additions to prevent clumping.

Storage Requirements

_{^{Crucial for stability}}

Amoxicillin suspension is stable at room temperature for 14 days, though refrigeration improves the taste. Amoxicillin-Clavulanate suspension MUST be refrigerated and discarded after 10 days.

Accurate Administration

_{^{Avoid household spoons}}

Advise shaking well before each use. Always dispense and counsel the use of an oral syringe for accurate weight-based dosing. Take with food (especially Augmentin) to decrease GI upset.

Emphasize completing the entire 5 to 10-day course, even if the child feels completely better after 2 days, to prevent relapse and antibiotic resistance.