title: X-type histiocytosis
text: # X-type histiocytosis
  
  X-type histiocytoses are a clinically well-defined group of cutaneous syndromes characterized by infiltrates of Langerhans cells, as opposed to Non-X histiocytosis in which the infiltrates contain $monocytes/macrophages.^{:720}$ Conditions included in this group $are:^{:720–4}$
  
     * Congenital self-healing reticulohistiocytosis
  
     * Langerhans cell histiocytosis
  