**Question:** Recurrent plaques on glans which heal with residual hyperpigmentation is seen with:

A. Lichen planus
B. Lichen sclerosus
C. Lichen simplex chronicus
D. Lichen nitidus

**Core Concept:** Lichen planus is a chronic inflammatory disease characterized by the formation of papules and plaques on the skin, mucous membranes, and nails. It is caused by an immune system response against basal cells in the epidermis.

**Why the Correct Answer is Right:** Recurrent plaques on the glans, which heal with residual hyperpigmentation, is a clinical manifestation of Lichen planus. The plaques are caused by an immune response against basal cells in the epidermis, leading to inflammation and tissue damage. The resulting healing process results in residual hyperpigmentation, which is seen in this particular case.

**Why Each Wrong Option is Incorrect:**

A. Lichen sclerosus: This condition results in atrophy and white, atrophic plaques, not hyperpigmentation. It primarily affects the genital area and can cause urethral stricture.

B. Lichen sclerosus is similar to Lichen sclerosus but results in atrophic plaques, not hyperpigmentation.

C. Lichen simplex chronicus: This condition results in thickened, hyperkeratotic plaques, not papules and plaques with hyperpigmentation. It is a chronic inflammatory condition that results from prolonged and excessive itching and scratching.

D. Lichen nitidus: This condition presents as small, shiny, punctate keratotic lesions, not papules and plaques with hyperpigmentation. Lichen nitidus is a benign condition affecting both children and adults and is caused by keratinocyte hyperplasia.

**Clinical Pearl:** Lichen planus is a common dermatological condition affecting both sexes equally, typically appearing in middle-aged adults. It is characterized by bilateral, non-pruritic, violaceous papules and plaques on the genital area, causing hyperpigmentation on healing. The condition is commonly associated with oral ulcers and internal organs involvement like liver, kidney and bone marrow. Proper management includes topical corticosteroids, antimalarials, and immunosuppressive agents.