title: [Palmoplantar dermatoses: when should genes be considered?].
abstract: BACKGROUND
  Palmoplantar dermatoses are common. They can be both functionally debilitating and markedly stigmatize the patient because they are so visible. Dermatoses on the hands and feet often go along with palmoplantar hyperkeratosis. Such palmoplantar keratoses (PPK) can be classified into acquired (non-hereditary) and hereditary (monogenetic) PPK.
  
  
  OBJECTIVE
  A considerable proportion of PPK develop on the grounds of gene defects. As these diseases constitute a heterogeneous group of quite uncommon single entities, the treating physician must know when to entertain the diagnosis of a hereditary PPK and which causative genes should be considered.
  
  
  METHODS
  We summarize the common causes of acquired and hereditary PPK based on a review of the latest literature.
  
  
  RESULTS
  The most common causes of acquired PPK are inflammatory dermatoses like psoriasis, lichen planus, or hand and feet eczema. Also irritative-toxic (arsenic poisoning, polycyclic aromatic hydrocarbons) and infectious causes of PPK (human papilloma viruses, syphilis, scabies, tuberculosis, mycoses) are not uncommon. Genetically caused PPK may occur isolated, within syndromes or as a paraneoplastic marker. The clinical/histological classification discerns diffuse, focal, or punctuate forms of PPK with and without epidermolysis. A new classification based on the causative gene defect is starting to replace the traditional clinical classification.
  
  
  CONCLUSIONS
  Knowledge about the large, but heterogeneous group of hereditary PPK is important to adequately counsel and treat patients and their families.
authors.affiliation: Klinik für Dermatologie, Venerologie und Allergologie, Universitätsmedizin Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Deutschland.
authors.forename: C
authors.initials: C
authors.lastname: Seebode
authors.forename: S
authors.initials: S
authors.lastname: Schiller
authors.forename: S
authors.initials: S
authors.lastname: Emmert
authors.forename: K
authors.initials: K
authors.lastname: Giehl
mesh_terms: D020732:Cytogenetic Analysis / Q000379:methods*; D005819:Genetic Markers / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005820:Genetic Testing / Q000379:methods*; D006801:Humans; D007645:Keratoderma, Palmoplantar / Q000175:diagnosis* / Q000235:genetics*; D025202:Molecular Diagnostic Techniques / Q000379:methods*
chemical_list: D005819:Genetic Markers