In a 47-year-old man with an unremarkable medical history who developed a viral upper respiratory infection followed by myalgia, ear pressure, hearing loss, low‑grade fever, erythema of the tympanic membrane without otorrhea or mastoid tenderness, what is the most likely diagnosis?

Acute Otitis Media (AOM)

The most likely diagnosis is acute otitis media (AOM), a bacterial middle ear infection that developed as a complication of the preceding viral upper respiratory tract infection.

Clinical Reasoning

This 47-year-old man presents with the classic progression and features of AOM:

Diagnostic Criteria Met

The patient fulfills the established definition of AOM 1, 2:

1. Acute onset following viral URI - The temporal sequence is characteristic, with symptoms developing "after a few days" of the viral infection
2. Middle ear inflammation signs - Erythema of the tympanic membrane is a key finding
3. Symptoms of middle ear involvement - Ear pressure sensation, hearing loss (indicating middle ear effusion), and low-grade fever

Pathophysiologic Sequence

AOM is always preceded by viral upper respiratory infection 2. The viral URI causes Eustachian tube dysfunction through decreased mucociliary action, altered mucus secretion, and increased inflammatory mediators 3. This allows nasopharyngeal bacteria (Streptococcus pneumoniae and Haemophilus influenzae being most common 4) to ascend into the middle ear space 2.

Approximately 37% of viral URIs in susceptible individuals progress to AOM 2. The myalgia represents systemic viral symptoms, while the ear-specific complaints (pressure, hearing loss) indicate middle ear effusion development.

Key Distinguishing Features

• No mastoid tenderness - Rules out acute mastoiditis as a complication
• No discharge - Indicates intact tympanic membrane (no perforation or otorrhea)
• Erythema without bulging mentioned - Suggests early-to-moderate AOM rather than severe disease with marked bulging 1, 2
• Low-grade fever - Consistent with non-severe AOM (severe AOM defined as fever ≥39°C) 2

Alternative Diagnoses Excluded

Otitis externa is unlikely because 5:

• Otitis externa presents with tragal/pinna tenderness (absent here)
• It typically lacks the preceding URI and systemic symptoms
• Hearing loss is less prominent

Otitis media with effusion (OME) is excluded because 2:

• OME has fluid without signs of acute infection
• The acute onset, fever, and erythema indicate active inflammation characteristic of AOM

Clinical Implications

While AOM guidelines primarily address pediatric populations 1, 6, the diagnostic principles apply to adults. The patient requires:

• Pain management as a priority 1
• Observation versus antibiotics - In adults with non-severe disease (low-grade fever, no severe otalgia), observation for 48-72 hours is reasonable 1
• Antibiotic consideration if symptoms persist or worsen, with amoxicillin as first-line 1

The absence of mastoid tenderness and otorrhea indicates uncomplicated disease, but close follow-up is essential to detect potential complications.