Lichen Nitidus

Presents as tiny (1 to 2 mm), monomorphic, skin-colored, shiny, flat-topped papules often in a linear distribution that are the result of Köebnerization (Fig. 8.15).
The lesions usually occur in groups, and are seen primarily on the abdomen, chest, back, glans penis, and upper extremities.
The Köebner phenomenon is invariably present and is a clinical hallmark of LN (Fig. 8.16).
Nail involvement may occur in patients with palmar involvement and presents with linear ridges and pits.
Lesions are typically asymptomatic but occasionally itch.
LN is slowly progressive initially then tends to stabilize and regress spontaneously.

Diagnosis is easily made by clinical recognition.
Biopsy will show the very characteristic “ball in claw” pattern where elongated rete ridges at the margins appear to be grasping a focal circumscribed infiltrate of lymphocytes and histiocytes in the papillary dermis.

Differential Diagnosis

Molluscum Contagiosum (see Chapter 6: Superficial Viral Infections)

Skin-colored, pearly papules with central umbilication; may be spread by autoinoculation of viral particles (pseudo-Köebnerization).
Molluscum lesions are larger than those of LN and often are of various sizes.

Flat warts (see Chapter 6: Superficial Viral Infections)

Light brown flat-topped papules, may also be spread by autoinoculation (pseudo-Köebnerization).
Often variably sized lesions present.

Management

Localized asymptomatic cases may go unnoticed or be an incidental finding.
If asymptomatic no treatment is necessary.
Mid- to high-potency topical corticosteroids such as triamcinolone 0.1% ointment can alleviate pruritus symptoms, if present, and may hasten resolution.
Parents should be reassured of its benign nature and the tendency for spontaneous regression.