What should I do for a warm, swollen, painful left facial area?

Facial Cellulitis: Immediate Assessment and Management

This patient has facial cellulitis—a bacterial infection of the deep dermis and subcutaneous tissue—and requires urgent antibiotic therapy, with immediate evaluation to exclude orbital involvement or dental abscess as the source. 1, 2

Immediate Clinical Assessment

Determine if this is periorbital/orbital cellulitis versus facial cellulitis, as these are distinct entities requiring different management approaches 3, 4:

• Check for orbital involvement immediately: Look for proptosis, restricted eye movements, vision changes, or pain with eye movement—any of these findings indicate orbital cellulitis requiring IV antibiotics and urgent ophthalmology consultation 4
• Periorbital cellulitis (preseptal, limited to eyelids) is more common but less severe than orbital cellulitis (postseptal) 4
• Facial cellulitis without orbital involvement can typically be managed with oral antibiotics as an outpatient 1, 2

Search for the Infection Source

Identify the underlying cause, as this determines definitive treatment 5:

• Dental pathology is the most common source of maxillofacial cellulitis—examine for dental caries, periodontal disease, or recent dental procedures 5
• Skin trauma including minor cuts, insect bites, or abrasions often precede cellulitis 2
• Sinusitis can cause facial cellulitis, particularly in the periorbital region 3
• Perform bimanual palpation of salivary glands to exclude parotitis or submandibular gland infection 6

Red Flags Requiring Immediate Escalation

Recognize life-threatening complications that mandate hospital admission 5:

• Orbital signs: proptosis, ophthalmoplegia, or vision changes suggest orbital cellulitis requiring IV antibiotics and possible surgical drainage 4
• Systemic toxicity: high fever, rigors, or altered mental status may indicate bacteremia or intracranial extension 3
• Rapid progression or failure to respond to oral antibiotics within 48 hours 7
• Immunocompromised state or diabetes increases risk of necrotizing fasciitis and other severe complications 5

Antibiotic Selection

Start empiric oral antibiotics immediately for uncomplicated facial cellulitis 1, 2:

• Dicloxacillin or cephalexin are first-line choices when methicillin-resistant Staphylococcus aureus (MRSA) is not suspected 2
• Consider MRSA coverage (trimethoprim-sulfamethoxazole, doxycycline, or clindamycin) if there is local MRSA prevalence, purulent drainage, or recent antibiotic exposure 2
• IV antibiotics with broad coverage are required for orbital cellulitis, given the variety of potential pathogens including Streptococcus, Staphylococcus, and anaerobes 3, 4

Surgical Intervention

Surgical drainage is necessary in specific circumstances 5:

• Dental abscess requires extraction or root canal treatment in addition to antibiotics 5
• Orbital cellulitis with abscess formation requires surgical drainage in 49% of cases when medical therapy fails 4
• Incision and drainage of any fluctuant collection is essential for source control 1, 5

Common Diagnostic Pitfalls

Avoid misdiagnosing cellulitis mimics, which lead to unnecessary antibiotics and hospital admissions 7:

• Angioedema presents with facial swelling but lacks warmth and is not tender to touch—check for associated urticaria or medication triggers (ACE inhibitors) 6
• Contact dermatitis and venous stasis dermatitis can mimic cellulitis but have different distributions and lack systemic signs 2
• Giant cell arteritis in patients over 50 with unilateral facial pain requires immediate ESR and C-reactive protein to prevent vision loss 8

Follow-Up and Monitoring

Reassess within 48 hours to confirm treatment response 7:

• Expect improvement in erythema, warmth, and pain within 48-72 hours of starting antibiotics 7
• Switch to IV antibiotics and consider hospital admission if symptoms worsen or fail to improve 7
• Complete the full antibiotic course (typically 7-10 days) even after clinical improvement 2