Approach to the Problem
Swelling of the external ear may be a concerning symptom to parents. Most causes of ear swelling are benign. Insect bites, for example, are a common cause of ear swelling in pediatric patients. However, the swelling seen with insect bites and other benign entities may mimic other diseases, such as cellulitis, perichondritis, and mastoiditis, all of which require immediate attention. Otitis externa can become diffuse and cause external ear swelling with an appearance similar to cellulitis. Blunt trauma to the ear results in swelling and discoloration of the auricle, pinna, or both. Mastoiditis, an acute bacterial infection, causes swelling and erythema of the pinna and posterior auricular swelling and tenderness.
Key Points in the History
• Pruritus, associated with swelling and erythema, is the typical presentation of an insect bite to the ear.
• A previous history of ear piercing or laceration to the ear lobe should raise the suspicion for a keloid. Patients with keloids will often have a history of keloids on other parts of their body.
• Recent ear pain with or without drainage in conjunction with posterior auricular swelling, fever, or both may indicate mastoiditis.
• The duration of symptoms often helps to distinguish an insect bite from cellulitis. Swelling and erythema resulting from an insect bite occur suddenly, whereas the swelling, tenderness, and redness of cellulitis may gradually develop.
• A history of active or recent, localized acute otitis externa may result in cellulitis of the auricle or diffuse otitis externa.
• A history of paroxysmal ear burning, redness, and swelling may indicate otomelalgia (red ear syndrome).
Key Points in the Physical Examination
• Trauma, which may present as an auricular hematoma, and cellulitis typically present as swelling of the pinna and auricle, whereas mastoiditis presents as swelling and redness of the posterior auricular (e.g., in the area of the mastoid) and auricular areas.
• Forward displacement of the pinna usually indicates mastoiditis, although diffuse otitis externa or a posterior auricular insect bite may cause ear displacement when significant associated swelling is present.
• A rubbery, fleshy mass that extends beyond the wound margins indicates keloid formation.