The external ear is a defining anatomical feature susceptible to several pathologies. It consists of a uniquely shaped and bent elastic cartilage covered by thin skin and connects inferiorly with a lobule that is absent of cartilage but contains fibro-fatty tissue and a robust vascular supply. The ear cartilage is elastic and 1.0 to 3.0 mm thick depending on its location.¹ The ear protrudes at an angle of 25° to 30° from the skull base.¹ The cartilaginous regions of the external ear receive their blood supply through the tightly adherent overlying perichondrium, which is important to remember in treating trauma patients. The ear is robustly vascular and supplied by a helical arcade that is anteriorly and posteriorly supplied from the superficial temporal artery (STA) and posterior auricular artery (PAA), respectively. Although venous drainage can vary, blood is generally felt to egress via the postauricular vein into the external jugular, superficial temporal, and retromandibular venous systems.^1,2 The external ear is innervated from branches of the trigeminal, vagus, facial, and great auricular nerves.

The history of a trauma patient should include the context of the injury and the likelihood for future episodes. Tetanus vaccination history should be elicited. Head and neck bony and soft tissue anatomy should be carefully examined for associated injuries, and the patient should be assessed for Battle sign, which may indicate the presence of a skull base fracture.⁸ An otoscopic examination evaluates for hemotympanum, and a tuning fork examination should be considered in patients who endorse hearing loss.

In patients presenting with preceding trauma or other penetration of skin, development of redness and painful swelling of the pinna should prompt the emergency provider to consider perichondritis. Patients often experience an initial dull indolent ache with redness and swelling involving the helix and antihelix, which later may progress to involve the entire cartilage, producing a “loss of contours” appearance.⁴ On examination, it is important to carefully assess for fluctuance, which indicates the development of abscess and necessitates ENT consultation for incision and drainage. In later stages, spontaneous fluid may drain from the wound and an eventual deformity of the ear known as “cauliflower ear” can form. This deformity may occur even after proper hematoma incision and drainage but is far more likely in cases where continued chondritis and necrosis are allowed to occur unabated.

Generally, perichondritis is unlikely to cause critical illness, and evaluation for an alternative cause with systemic illness is important. However, in an immunocompromised host, pseudomonal infection can progress rapidly and spread to involve the parotid gland, facial nerve, external auditory canal, middle ear, temporal bone, and central nervous system (CNS).