Epidermal Inclusion Cyst

Key Features

• Firm dermal papule or nodule

• Overlying black comedone or "punctum"

• Expressible foul-smelling cheesy material

• May become red and drain, mimicking an abscess

Clinical Findings

• Benign growths of the upper portion of the hair follicle

• Common in Gardner syndrome and may be the first sign of the condition

• Favor the face and trunk

• May complicate nodulocystic acne vulgaris

• Individual lesions range in size from 0.3 cm to several centimeters

Diagnosis

• Cultures of the expressed material will be sterile

Treatment

• Not required if asymptomatic

• Inflamed lesions may be treated with incision and drainage or intralesional triamcinolone acetonide 5–10 mg/mL

• For large or symptomatic cysts, surgical excision is curative