What is the differential diagnosis for ENT-related issues affecting the face, shoulder, and arms?

Differential Diagnosis for ENT-Related Issues Affecting Face, Shoulder, and Arms

When a patient presents with combined ENT symptoms and upper extremity involvement (shoulder/arm pain, weakness, or paresthesias), the primary diagnostic consideration is neurogenic thoracic outlet syndrome (NTOS), which accounts for over 90% of TOS cases and commonly coexists with cervical pathology, though systemic vasculitides—particularly granulomatosis with polyangiitis (GPA)—must be excluded when ENT symptoms include nasal crusting, bleeding, or constitutional symptoms. 1, 2

Primary Diagnostic Categories

Neurogenic Thoracic Outlet Syndrome (Most Common)

• NTOS results from brachial plexus compression, typically from scarred scalene muscles secondary to neck trauma or whiplash injuries 1
• Presents with extremity paresthesias, pain, and weakness combined with neck pain and occipital headache 1
• The Adson test (radial pulse deficit) has no clinical value and should not be used—it is normal in most NTOS patients and positive in many healthy controls 1
• Key provocative maneuvers include:
  • Neck rotation and head tilting eliciting contralateral extremity symptoms 1
  • Upper limb tension test (comparable to straight leg raising) 1
  • Arms abducted to 90 degrees in external rotation bringing on symptoms within 60 seconds 1

Cervical Radiculopathy with Referred Pain

• Unilateral arm pain, weakness, and sensory loss can mimic TOS but originates from cervical nerve root compression 3
• Differentiation requires electrodiagnostic nerve studies to localize the lesion 4, 3
• Older patients may have neuralgic amyotrophy (Parsonage-Turner syndrome) presenting similarly 3

Systemic Vasculitis: Granulomatosis with Polyangiitis (GPA)

GPA must be considered when ENT symptoms are accompanied by systemic manifestations, as two-thirds of patients initially present with ENT-related symptoms 2

Critical ENT Manifestations of GPA:

• Rhinological symptoms (40% of initial presentations): nasal crusting (75%), discharge (70%), stuffiness (65%), bleeding (59%), facial pain (33%) 2
• Otologic symptoms (15% of initial presentations): hearing loss (conductive, sensorineural, or mixed), vertigo, tinnitus, facial nerve palsy 2
• Characteristic supratip nasal collapse (18-25%) with or without septal perforation (up to 30%) 2
• Endoscopy reveals friable, granular mucosa covered with old blood and crust 2

Systemic Features Distinguishing GPA:

• Disproportionate constitutional symptoms: profound unwellness, fatigue, weight loss, night sweats despite relatively minor upper respiratory symptoms 2
• Subglottic stenosis (16%) causing dyspnea, hoarseness, or inspiratory stridor 2
• Diagnosis is often delayed 6+ months, with ENT symptoms associated with >8 months delay 2

Diagnostic Testing for GPA:

• c-ANCA with proteinase-3 (PR3) is 99% specific and confirms diagnosis in 95% of active systemic disease 2
• Sensitivity drops to 50% in limited disease or after corticosteroid therapy—negative ANCA does not exclude GPA 2
• Elevated ESR, CRP, abnormal renal function (proteinuria, microscopic hematuria) 2
• Order ANCA testing in any patient with nasal crusting and bleeding, especially if disproportionately unwell 2

Eosinophilic Granulomatosis with Polyangiitis (EGPA)

• EGPA should be considered in any patient with severe nasal polyposis not responding to conventional therapy 2
• Characterized by adult-onset asthma (mean 8 years before vasculitis), allergic rhinitis (43%), and CRS with (54%) or without polyps (70%) 2
• Nasal obstruction (95%), crusting (75%), bleeding (60%), rhinorrhea (95%), facial pain, anosmia (90%) 2
• Peripheral eosinophilia usually >1500 cells/μL or >10% 2
• p-ANCA/MPO positive in some cases, though less specific than c-ANCA for GPA 2

Algorithmic Diagnostic Approach

Step 1: Characterize the ENT Component

• If nasal crusting, bleeding, and constitutional symptoms predominate: Obtain c-ANCA/PR3, ESR, CRP, urinalysis, chest imaging 2
• If severe nasal polyposis with asthma: Check peripheral eosinophil count, consider EGPA 2
• If isolated neck/shoulder/arm symptoms without significant ENT pathology: Proceed to neurovascular evaluation 1, 3

Step 2: Perform Targeted Physical Examination

• For suspected NTOS: Neck rotation/head tilting, upper limb tension test, 90-degree arm abduction test 1
• For suspected GPA: Nasal endoscopy looking for friable, granular mucosa with crusting; assess for hearing loss, facial nerve palsy 2
• For cervical radiculopathy: Spurling's test, assess dermatomal sensory loss and myotomal weakness 3

Step 3: Order Appropriate Diagnostic Studies

• Vascular TOS (rare, <1%): Duplex imaging has replaced angiography for subclavian vessel compression 4
• NTOS: Electrophysiological nerve studies and anterior scalene muscle blocks guide surgical candidacy 4
• GPA/EGPA: Tissue biopsy showing necrotizing granulomas with vasculitis, though sinonasal tissue may show only eosinophilic infiltration without classic vasculitis 2
• Cervical pathology: MRI cervical spine, electrodiagnostic studies 3

Critical Diagnostic Pitfalls

• Never rely on the Adson test for TOS diagnosis—it lacks clinical validity 1
• Do not dismiss GPA based on negative c-ANCA alone, especially in limited disease or after steroid treatment 2
• Recognize that >50% of GPA patients saw an ENT surgeon before diagnosis, yet experienced >8 months diagnostic delay 2
• NTOS is frequently misdiagnosed as "vascular TOS"—true vascular TOS is rare and presents with arm swelling/cyanosis (venous) or ischemia (arterial) 1
• In patients with both ENT and upper extremity symptoms, systematically exclude systemic vasculitis before attributing symptoms solely to mechanical compression 2, 1
• GPA patients presenting with ENT involvement have significantly better 5-year survival (98% vs 78%) compared to other systemic presentations, making early ENT recognition critical 2