Lichen Nitidus

Lichen nitidus clinically presents as multiple shiny, pinhead-sized, flesh-colored, dome-shaped papules typically involving the genitalia, upper extremities, and torso, though it also can be generalized. Lichen nitidus is a chronic eruption that classically appears in children and young adults. Although the eruption usually is asymptomatic, itching and/or a burning sensation occasionally have been reported. Histologically, there is a sharply circumscribed inflammatory infiltrate within the dermis that generally spans approximately 4 to 5 dermal papillae. The borders are marked by extensions of epidermal ridges, giving a ball-in-claw appearance. The infiltrate is composed of lymphocytes and epithelioid histiocytes. The overlying epidermis is parakeratotic with basal cell hydropic degeneration and cytoid bodies.