Demodicidosis of an Intertragic Notch of the Ear That Was Misdiagnosed as a Skin Tumor: A Case Report

Abstract

<i>Demodex</i> mite infestation has variable clinical manifestations including eruptions, erythema, pustules, facial hyperpigmentation, rosacea-like lesions, and perioral dermatitis. A 62-year-old man came with a 2-year history of a slowly enlarging, asymptomatic lesion in the intertragic notch of the left ear, and the findings from an ultrasound conducted by a radiologist suggested a benign skin tumor such as an epidermal or trichilemmal cyst. After total excision, histopathology of a section of the specimen showed multiple follicular infundibula containing <i>Demodex</i> folliculorum in the dermal layer, and the perifollicular tissue showed granulomatous change with lymphomononuclear inflammation. This article presents a rare clinical symptom of <i>Demodex</i> mites in the form of a tumor-like lesion on the face.