What are the differential diagnoses for a patient with recurrent ear pain, mild unilateral mastoid (inflammation of the mastoid bone) tenderness, and intermittent parotid (salivary gland) swelling, despite a negative exam?

Differential Diagnoses for Recurrent Ear Pain with Negative Exam, Mild Unilateral Mastoid Tenderness, and Intermittent Parotid Swelling

The most likely diagnosis is recurrent parotitis, which characteristically presents with intermittent parotid swelling and can cause referred otalgia without abnormal otoscopic findings, particularly given the constellation of symptoms and negative ear examination. 1

Primary Differential Considerations

Recurrent Parotitis (Most Likely)

• Recurrent parotitis typically affects children aged 3-6 years and presents with intermittent parotid swelling and pain that can refer to the ear region. 1
• The condition is caused by congenital abnormalities of salivary gland ducts with recurrent ascending infections, often aided by dehydration. 1
• Males are more commonly affected in childhood, while females predominate when disease starts after puberty. 1
• Symptoms usually subside at puberty, with most patients symptom-free by age 22. 1
• Ultrasound is the appropriate initial investigation, typically supplemented by sialography, which may itself cause symptom resolution. 1, 2
• Treatment is conservative initially with expectant management; more aggressive interventions (parotid duct ligation, parotidectomy, or interventional radiology procedures) are reserved for adults with persistent problems. 1, 2

Referred Otalgia from Non-Otologic Sources

• Temporomandibular joint (TMJ) syndrome is the most common cause of referred otalgia with normal ear examination, presenting with pain radiating to the periauricular area, temple, or neck. 3
• Patients often report gum chewing, bruxism, or recent dental procedures with subsequent malocclusion. 3
• Examination reveals tenderness over the affected TMJ with possible associated crepitus. 3
• Dental pathologies (caries, impacted molars) can cause referred ear pain without otoscopic abnormalities. 3

Early or Subclinical Mastoiditis

• Acute mastoiditis can present with mastoid tenderness and ear pain, though typically with more obvious clinical findings including postauricular erythema, swelling, and pinna displacement. 4, 5
• The condition represents a continuum from acute otitis media, and 72% of cases occur in patients with no previous middle ear disease history. 4
• Antibiotic treatment for acute otitis media cannot be considered absolute safeguard against acute mastoiditis. 4
• When mastoiditis is suspected, imaging (CT temporal bones) is warranted to evaluate for coalescent mastoiditis or subperiosteal abscess. 6
• Common organisms include Streptococcus pneumoniae, Streptococcus pyogenes, Staphylococcus aureus, and gram-negative organisms. 4

Otitis Media with Effusion (OME)

• OME presents with middle ear effusion behind an intact tympanic membrane without acute infectious symptoms like fever or acute ear pain. 7
• The absence of acute infectious symptoms distinguishes OME from acute otitis media, though conductive hearing loss is the hallmark feature. 7
• Limited or absent tympanic membrane mobility would be evident on pneumatic otoscopy if OME were present. 7

Critical Diagnostic Approach

Key Examination Findings to Differentiate

• Assess for tragal tenderness, which if present suggests otitis externa rather than referred pain or parotitis. 8
• Examine the parotid gland bilaterally for asymmetry, swelling, or tenderness during symptomatic periods. 1
• Palpate the TMJ for tenderness and crepitus while the patient opens and closes the mouth. 3
• Inspect the postauricular area for erythema, swelling, or pinna displacement that would indicate overt mastoiditis. 4, 6
• Perform pneumatic otoscopy to assess tympanic membrane mobility and rule out middle ear effusion. 7

Recommended Diagnostic Workup

• Ultrasound of the parotid gland is the appropriate initial investigation when recurrent parotitis is suspected. 1
• Consider sialography if ultrasound suggests ductal abnormalities, as this may be both diagnostic and therapeutic. 1, 2
• CT temporal bones is indicated if clinical concern for mastoiditis persists despite negative otoscopy, particularly with persistent mastoid tenderness. 5, 6
• Dental evaluation should be pursued if TMJ syndrome or dental pathology is suspected. 3

Common Pitfalls to Avoid

• Do not prescribe antibiotics for recurrent parotitis without evidence of acute bacterial infection, as the condition is managed conservatively. 1
• Avoid misdiagnosing referred otalgia as otitis media and prescribing unnecessary antibiotics when the ear examination is normal. 3, 7
• Do not dismiss mild mastoid tenderness in the setting of recurrent symptoms; subclinical or masked mastoiditis can present subtly before developing complications. 4
• Recognize that older patients with tobacco/alcohol use and otalgia with normal ear exam require complete head and neck examination to exclude upper aerodigestive tract malignancy. 3
• Intracranial complications of mastoiditis can appear concomitant with or soon after first signs, so maintain high index of suspicion. 4