Lichen nitidus is a chronic inflammatory disease of unknown cause  characterized by 1–2 mm, discrete and uniform, shiny, flat-topped, pale flesh-colored or reddish-brown papules that may appear as hypopigmented against dark skin. Occasionally, minimal scaling is present or can be induced by rubbing the surface of the papules. The disease usually affects children and young adults and is painless and usually nonpruritic, although protracted itching may occur in some cases. It is sometimes referred to by dermatologists as "mini lichen planus". Presentation
Linear arrangements of these papules is common (referred to as a Koebner phenomenon), especially on the forearms, but may occasionally be grouped, though not confluent, on flexural areas. Generally, the initial lesions are localized, and remain so, to the chest, abdomen, glans penis, and flexor aspects of the upper extremities; however, less commonly, the disease process can (1) be strictly isolated to the palms and soles, presenting with many hyperkeratotic, yellow papules that may coalesce into plaques that fissure or “...sometimes a non-specific keratoderma resembling chronic eczema,” or (2) become more widespread, with papules widely distributed on the body—the extensor surfaces of the elbows, wrists, and hands, folds of the neck, submammary region in females, groin, thighs, ankles, and feet—and fusing into erythematous, minimally scaled plaques, with redness that develops tints of violet, brown, and yellow.
However, as the surveys Arab test persons were mainly recruited from a handful of large and closely related clans living in a particular village, said percentage should be considered with some reservation, according to Goodman et alia (1965). Cases of stub thumbs have also been found in Eastern Nepal for Jirel ethnic individuals from their participation in various epidemiologic studies. Some studies included taking radiographs of hands and wrists to examine their skeletal structure. Of the studied sample (which included 2,130 participants; 969 male and 1,161 female), 3.55% were found to have brachydactyly type D.

Terminology
The condition is known under numerous names. The most commonly used name is clubbed thumb, or club thumb. American researcher R.A. Hefner used the terms "short thumb" and "brachymegalodactylism" in 1924, and "short thumb" has continued to be used in a few other studies since then, including the study that defined Rubinstein–Taybi syndrome in 1963. "Stub thumb" is the common term preferred by the online database Online Mendelian Inheritance in Man and was first used in a 1965 study. Stub thumbs have also been called murderers thumb (allegedly among fortune tellers), bohemian thumb, toe thumb, and potters thumb.The term "clubbed thumb" should not be confused with nail clubbing, which is a clinical sign associated with a number of diseases. == References ==