Keratin 9 (K9) is a type I intermediate filament protein whose expression is confined to the suprabasal layers of the palmoplantar epidermis. Although mutations in the K9 gene are known to cause epidermolytic palmoplantar keratoderma, a rare dominant-negative skin disorder, its functional significance is poorly understood. To gain insight into the physical requirement and importance of K9, we g...

Sir, Palmoplantar keratodermas (PPKs) constitute a heterogeneous group of skin disorders with the distinctive trait of hyperkeratosis of palmoplantar skin. The disorders are classified clinically by the morphology and distribution of the hyperkeratosis, the presence of associated cutaneous and non-cutaneous features and by the mode of transmission (1, 2). Familial diffuse epidermolytic PPK (EPP...

Reported for the first time in 1996, aquagenic keratoderma is a rare condition which is characterized by edematous flat-topped papules appearing on palmar skin after water immersion. Multiple anecdotal associations have been described but, recently, the association with cystic fibrosis gene mutations (CFTR) has been highlighted. The authors describe an 18 year-old female, with one-month complai...

Focal acral hyperkeratosis (FAH) is a rare genodermatosis. FAH usually observed in the second or third decades of life, and it type palmoplantar keratoderma, heterogeneous group diseases characterized by abnormal incrassation palms soles. Although an autosomal dominant inher- itance, could also be sporadic. It known as variant Costa’s Acrokeratoelastoidosis (AKE). Its etiology not clearly there...

An 8-year-old girl with the classic findings of keratoderma hereditaria mutilans (Vohwinkel's syndrome) was seen. Treatment with isotretinoin was instituted to decrease the hyperkeratosis and to prevent further autoamputation. After a 12-week course at 2 mg per kg per day, the patient had only minimal decrease in the amount of hyperkeratosis. Because of the well-known long-term risks of systema...

espanolLa pitiriasis rubra pilaris es una dermatosis infrecuente cuya etiologia se desconoce; caracteriza por papulas foliculares hiperqueratosicas, placas eritematosas y escamosas que pueden progresar a eritrodermia, con islas de piel sana, queratodermia palmoplantar. Los subtipos III, IV V, segun la clasificacion Griffiths, observan exclusivamente en ninos. El tratamiento esta constituye un d...

P rimary biliary cirrhosis (PBC) is an autoimmune disease of the liver characterized by the presence of highly specific antimitochondrial antibodies with resulting immune-mediated injury of small intrahepatic bile ducts. Palmoplantar keratodermas (PPKs) are characterized by hyperkeratosis of the skin on the palms and soles. Multiple cases have been reported associating PPK with autoimmune thyro...

We present a case of a 48-year-old man with an approximately 30-year history of spiny projections on the palms, which were histopathologically consistent with spiny keratoderma. Spiny keratoderma is a rare entity of unknown etiology that has been described with both hereditary and acquired variants. The hereditary form, which is most likely the diagnosis in our patient, manifests at a younger a...