Ruptured epidermal inclusion cyst of the palm presenting as collar-button abscess.

Two cases of epidermal inclusion cysts that ruptured as a result of trauma and then mimicked pyogenic collar-button abscesses are reported. Rupture of the cyst into the palmar subcutaneous tissue produced an inflammatory response that led to the sterile abscesses drained at surgery. Presentation of a deep space abscess without history of penetrating injury should suggest this diagnosis.