Pachyonychia congenita (PC) is a rare genodermatosis caused by mutations in any of the four genes KRT6A, KRT6B, KRT16, or KRT17, which can lead to dystrophic, thickened nails and focal palmoplantar keratoderma, among other manifestations. Although classically subdivided into two major variants, PC-1 (Jadassohn-Lewandowski syndrome) and PC-2 (Jackson-Lawler syndrome), according to the localizati...

Heinrich Köbner (1838-1904) was the founder of the dermatology clinic in Breslau (Germany, now Wroclaw, Poland) which was later led by the famous Neisser and Jadassohn. He described his eponymic phenomenon in 1872 in a case of psoriasis. This phenomenon was recognized by his contemporaries such as Kaposi and Darier « les frottements continus ou les pressions répétées semblent lui servir de caus...

Observation: Primary anetoderma is very uncommon in childhood. The exact pathogenesis and curative treatment of anetoderma are still unknown. We report a 12 -year-old girl presented with multiple elevated or herniated, circumscribed, skin-coloured papules which initially emerged as erythematous macules over her neck, trunk, upper and lower extremities. Histopathological examination of a papular...

Pachyonychia congenita (PC) is a rare genodermatosis affecting the nails and other ectodermal tissues. It is mainly characterized by gross thickening of all finger and toe nails. Different additional clinical features are observed; they fit into two major types: the Jadassohn-Lewandowsky and the Jackson-Lawler syndrome. The condition is usually transmitted as an autosomal dominant trait, though...