What is the differential diagnosis and urgent management for an adult with acute right‑sided facial swelling that began overnight and is accompanied by numbness of the cheek?

Acute Right-Sided Facial Swelling with Cheek Numbness

This patient requires immediate emergency department evaluation to rule out invasive fungal rhinosinusitis, stroke, or acute arterial occlusion—all life-threatening conditions that demand intervention within hours to prevent permanent disability or death.

Immediate Life-Threatening Differentials

Invasive Fungal Rhinosinusitis (Mucormycosis)

The combination of unilateral facial swelling with facial numbness is a hallmark presentation of invasive fungal disease and constitutes a medical emergency. 1

• Key clinical features: Facial pain, facial swelling, nasal obstruction, and numbness of the face or palate occur in 50–65% of patients 1
• Critical warning sign: Numbness indicates tissue destruction from angioinvasion by fungal hyphae, causing thrombosis and tissue necrosis 1
• High-risk populations: Almost exclusively occurs in immunocompromised patients (diabetes, neutropenia, aplastic anemia, renal/hepatic failure) 1
• Mortality: Overall survival is only 50% even with treatment 1

Stroke (Cerebrovascular Accident)

Acute unilateral facial numbness with or without swelling requires immediate stroke evaluation. 2

• Time-critical: Patients presenting within 48 hours have a 10% risk of completed stroke within the first week, with highest risk in the first 48 hours 2
• Associated symptoms to assess: Facial weakness, arm weakness, speech difficulty, visual changes, or confusion 1, 2
• Isolated numbness alone (hemibody sensory loss) still represents high stroke risk 2

Acute Arterial Occlusion

Assess the "6 P's" immediately: Pain, Pallor, Pulselessness, Paresthesias (numbness), Poikilothermia (cool limb), Paralysis 2

• Check radial pulse and blood pressure in both arms 2
• Absent pulse or unmeasurable blood pressure requires immediate vascular surgery consultation 2

Secondary Urgent Differentials

Acute Bacterial Sinusitis with Complications

• Orbital involvement: Swelling, diplopia, or proptosis indicates orbital cellulitis requiring urgent evaluation 1
• Intracranial extension: Altered mental status, severe headache, or neck stiffness 1
• Typical presentation: Purulent nasal discharge, facial pain/pressure, fever, symptoms >10 days or worsening after initial improvement 1

Parotid Gland Pathology

• Malignancy indicators: Facial nerve palsy, trismus, rapid growth, or fixed mass 3
• Acute sialadenitis: Painful swelling, purulent discharge from Stensen's duct, fever 3

Trigeminal Neuropathy from Malignancy

Progressive facial numbness may represent the earliest symptom of malignancy or autoimmune disease as sensory neurons are destroyed. 4

• Perineural tumor spread along cranial nerve V branches causes numbness before mass effect produces swelling 4
• Requires periodic evaluation and vigilance even years after presentation if no diagnosis is made 4

Urgent Management Algorithm

Step 1: Immediate Assessment (Within Minutes)

• Vital signs: Temperature, blood pressure in both arms, pulse, respiratory rate 1
• Stroke screen: Facial droop, arm drift, speech abnormality (Cincinnati Stroke Scale has 72% probability if any one abnormal) 1
• Vascular assessment: Radial pulse, capillary refill, skin temperature 2
• Airway assessment: Trismus, tongue swelling, stridor 1

Step 2: Focused Physical Examination

• Nasal endoscopy (if available): Look for necrotic tissue on middle turbinate, palate, or lateral nasal wall—this is pathognomonic for invasive fungal disease 1
• Oral cavity: Purulent drainage in posterior pharynx, palatal necrosis, dental infection 1
• Eye examination: Proptosis, ophthalmoplegia, visual changes, periorbital edema/erythema 1
• Neurologic examination: Cranial nerve function, motor/sensory deficits, mental status 1, 2

Step 3: Risk Stratification for Invasive Fungal Disease

Immediately assess immunocompromised status: 1

• Diabetes (especially poorly controlled)
• Active chemotherapy or neutropenia
• Solid organ or bone marrow transplant
• Chronic corticosteroid use
• HIV/AIDS
• Aplastic anemia
• Renal or hepatic failure

If ANY immunocompromise + facial swelling + numbness → Assume invasive fungal rhinosinusitis until proven otherwise

Step 4: Immediate Imaging

For suspected invasive fungal disease or stroke: 1, 2

• CT head without contrast to rule out hemorrhage and assess sinuses (can be done immediately) 1, 2
• MRI with contrast is more sensitive (86% vs 69% for CT) for detecting invasive fungal disease—look for loss of contrast enhancement 1
• CT angiography from aortic arch to vertex if stroke suspected 2

For suspected bacterial sinusitis complications: 1

• CT sinuses with contrast to evaluate orbital or intracranial extension

For suspected parotid pathology: 3

• Ultrasound initially, then MRI with and without contrast for deep lobe involvement

Step 5: Urgent Laboratory Studies

If invasive fungal disease suspected: 1

• Complete blood count with differential (assess neutropenia)
• Comprehensive metabolic panel (renal/hepatic function)
• Hemoglobin A1c and glucose (diabetes control)
• Serum galactomannan and (1,3)-beta-D-glucan (80% sensitivity/specificity for Aspergillus) 1
• Blood cultures

Step 6: Tissue Diagnosis

For invasive fungal disease: 1

• Urgent endoscopic biopsy with frozen section of any necrotic tissue
• Histopathology must demonstrate hyphal forms within mucosa, submucosa, blood vessels, or bone 1
• Zygomycetes: non-septate hyphae with wide-angle branching 1
• Aspergillus: septate hyphae with acute 45-degree branching 1

Definitive Treatment Based on Diagnosis

If Invasive Fungal Rhinosinusitis Confirmed

Three mandatory interventions: 1

1. Start systemic antifungal therapy immediately (liposomal amphotericin B preferred—60% survival vs other agents) 1
2. Urgent endoscopic or open surgical debridement of all necrotic tissue (ESS: 64% survival; open surgery: 54% survival) 1
3. Reduce immunosuppression when feasible (discontinue corticosteroids, optimize diabetes control) 1

If Stroke Confirmed

• Transfer to comprehensive stroke center with tPA and thrombectomy capability 2
• Dual antiplatelet therapy (aspirin + clopidogrel 75 mg for 21 days) if large vessel stenosis without revascularization 2

If Bacterial Sinusitis with Complications

• High-dose amoxicillin-clavulanate or cefuroxime axetil for 10–14 days 1
• Urgent ENT consultation for orbital or intracranial extension requiring surgical drainage 1

Critical Pitfalls to Avoid

• Never dismiss facial numbness as "just sinusitis"—numbness indicates tissue destruction or neurologic involvement 1, 4
• Do not delay imaging or ENT consultation in immunocompromised patients—invasive fungal disease progresses rapidly to cavernous sinus thrombosis (25% mortality) and intracranial extension 1
• Do not assume imaging alone can differentiate benign from malignant causes—tissue diagnosis is mandatory 3, 4
• Do not treat empirically with antibiotics alone if invasive fungal disease is possible—antibiotics worsen outcomes by delaying appropriate antifungal therapy 1
• Do not miss the stroke time window—every minute counts for tPA (4.5-hour window) and thrombectomy (24-hour window in selected patients) 2, 5