What is the appropriate evaluation and management for a tender lesion on the pinna?

Evaluation and Management of a Tender Lesion on the Pinna

Initial Assessment: Distinguish Between Infection and Other Pathology

The first priority is to determine whether this represents acute otitis externa with pinna involvement, perichondritis, cellulitis, or a non-infectious process through targeted physical examination.

Critical Physical Examination Elements

• Assess tragal and pinna tenderness – intense tenderness disproportionate to visual findings strongly suggests acute otitis externa with regional extension 1
• Examine the external auditory canal for edema, erythema, debris, or otorrhea, as diffuse canal inflammation confirms otitis externa 1, 2
• Evaluate the tympanic membrane when possible to assess integrity, as this determines topical antimicrobial selection 1, 2
• Inspect for cartilage involvement – painful swelling, warmth, and redness that spares the earlobe indicates perichondritis requiring immediate systemic fluoroquinolones to prevent cartilage necrosis 3
• Examine the scalp and postauricular skin for ulcerations, pigmented lesions, or primary infection sources 1, 4
• Palpate regional lymph nodes (preauricular, postauricular, cervical) for size, tenderness, and mobility, as regional lymphadenitis can accompany otitis externa 1, 4

Key Diagnostic Differentiators

A nontender neck mass is more suspicious for malignancy than a tender mass, but pinna lesions with acute tenderness typically represent infection rather than neoplasm 1. However, examine for concerning features: asymmetry, irregular borders, heterogeneous color, diameter >7mm, or recent evolution (ABCDE criteria), which may suggest melanoma or other cutaneous malignancy requiring excisional biopsy 1.

Management Algorithm Based on Clinical Findings

If Acute Otitis Externa with Pinna Extension

Topical fluoroquinolone drops (ofloxacin 0.3% or ciprofloxacin 0.2%) are the definitive first-line treatment, NOT oral antibiotics 2. This approach achieves 65-90% clinical cure rates within 7-10 days 2.

Essential Pre-Treatment Steps

• Perform aural toilet using gentle suction, dry mopping, or irrigation with body-temperature water/saline to remove debris, cerumen, and inflammatory material before administering drops 2, 3
• Avoid irrigation in diabetic or immunocompromised patients; use only atraumatic suction under microscopy to prevent necrotizing otitis externa 2
• Place a compressed cellulose wick if severe canal edema prevents drop entry or tympanic membrane visualization 2

Topical Antimicrobial Selection

• Use non-ototoxic fluoroquinolones (ofloxacin 0.3% or ciprofloxacin 0.2%) when tympanic membrane integrity is uncertain 2, 3
• Avoid aminoglycoside-containing drops (neomycin/polymyxin B) when perforation is suspected due to ototoxicity risk 2
• Avoid neomycin preparations in patients with eczema or contact dermatitis history, as neomycin causes sensitivity in 13-30% of chronic otitis externa patients 2

Indications for Adding Systemic Antibiotics

Reserve oral antibiotics for specific high-risk situations 2, 3:

• Extension of infection beyond the ear canal (cellulitis of pinna or adjacent skin)
• Diabetes mellitus or immunocompromised state
• Severe canal edema preventing adequate topical delivery despite wick placement
• Failure to improve after 48-72 hours of appropriate topical therapy

When systemic antibiotics are indicated, use fluoroquinolones (ciprofloxacin 500mg twice daily) to cover Pseudomonas aeruginosa and Staphylococcus aureus, which cause 98% of bacterial ear infections 2, 3.

If Perichondritis (Cartilage Involvement)

Start systemic fluoroquinolones immediately if the posterior pinna shows painful swelling, warmth, and redness that spares the earlobe, as this represents perichondritis requiring urgent treatment to prevent devastating cartilage necrosis and permanent ear deformity 3. Acute tenderness when deflecting auricular cartilage distinguishes this deeper infection from superficial cellulitis 3.

If Suspicious Pigmented or Ulcerated Lesion

Perform complete excision with 2mm margins under local anesthesia if the lesion shows asymmetry, irregular borders, heterogeneous color, diameter >7mm, or recent evolution 1. Send all excised tissue for histopathological examination; never use laser or electrocautery as tissue destruction compromises diagnosis 1.

Pain Management

Assess pain severity and prescribe appropriate analgesics 2, 3:

• Mild-to-moderate pain: acetaminophen 650-1000mg every 6 hours or ibuprofen 400-600mg every 6 hours
• Severe pain: short-term opioid-containing analgesics for the first 48-72 hours
• Pain typically improves within 48-72 hours of starting appropriate treatment 2, 3

Reassessment and Treatment Failure

Reassess within 48-72 hours if no improvement 2. Common causes of treatment failure include:

• Inadequate drug delivery due to canal obstruction or poor adherence
• Allergic contact dermatitis from topical agents (especially neomycin or hydrocortisone)
• Fungal co-infection (otomycosis), particularly in diabetics
• Incorrect diagnosis (chronic suppurative otitis media, necrotizing otitis externa, dermatologic disorder)

Critical Pitfalls to Avoid

• Prescribing oral antibiotics for uncomplicated otitis externa – 20-40% of patients inappropriately receive them despite topical therapy achieving superior cure rates (77-96% vs 30-67%) 2
• Using ototoxic preparations when tympanic membrane integrity is uncertain 2
• Skipping aural toilet before drop administration – medication cannot penetrate debris 2
• Irrigating the ear in diabetic or immunocompromised patients – can precipitate necrotizing otitis externa 2
• Missing perichondritis – requires immediate systemic antibiotics to prevent cartilage destruction 3
• Biopsy instead of excision for suspicious pigmented lesions – partial examination risks misdiagnosis 1