Epidermoid and Pilar Cysts
Epidermoid and pilar cysts are common benign subcutaneous nodules filled with keratin. They grow slowly but can become inflamed or infected.
Symptoms
Firm, round, mobile, skin-colored subcutaneous nodules, often with a central punctum. Rupture causes redness, tenderness, and foul-smelling discharge.
Causes and risk
Epidermoid cysts form from occluded follicles. Pilar cysts arise from hair follicle root sheaths and may be familial. Trauma and acne increase risk.
How it is evaluated
Clinical diagnosis. Ultrasound confirms cystic structure if uncertain. Excised cysts are sent for pathology.
Treatment
Asymptomatic cysts may be observed. Inflamed cysts need incision and drainage. Complete excision including the wall prevents recurrence. Our Chicago providers perform excisions under local anesthesia.