Lichen nitidus

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Lichen nitidus is a rare, chronic skin condition characterized by the presence of tiny, flesh-colored or slightly pink, shiny papules. These papules are typically uniform in size and shape, and they often appear in clusters. The condition is generally benign and asymptomatic, although it can sometimes cause mild itching.

Presentation

Lichen nitidus commonly presents as small, discrete, shiny papules that are usually 1-2 mm in diameter. These papules can appear anywhere on the body but are most frequently found on the trunk, upper extremities, genitalia, and flexor surfaces of the arms and legs. The papules are often described as "pinpoint" and may be slightly raised.

Pathophysiology

The exact cause of lichen nitidus is unknown. It is believed to be an inflammatory condition, possibly related to an abnormal immune response. Histologically, lichen nitidus is characterized by a dense, band-like infiltrate of lymphocytes and histiocytes in the upper dermis, often surrounding and obscuring the dermal papillae.

Diagnosis

The diagnosis of lichen nitidus is primarily clinical, based on the characteristic appearance of the papules. A skin biopsy can be performed to confirm the diagnosis, revealing the typical histopathological features. Differential diagnoses include lichen planus, molluscum contagiosum, and flat warts.

Treatment

Lichen nitidus is generally self-limiting and may resolve spontaneously without treatment. In cases where treatment is desired, options include topical corticosteroids, calcineurin inhibitors, and phototherapy. Systemic treatments are rarely needed.

Prognosis

The prognosis for lichen nitidus is generally good. The condition is benign and does not lead to serious complications. In many cases, the papules may resolve on their own over time, although they can persist for several years in some individuals.

Epidemiology

Lichen nitidus can affect individuals of any age, but it is most commonly seen in children and young adults. There is no known gender or racial predilection.

See also

• Lichen planus
• Dermatology
• Skin conditions