<prompt> A child presents with seborrheic dermatitis, sinusitis and chronically draining ears. On examination child has failure to thrive, with hepatosplenomegaly and exophthalmos, probable diagnosis is:Histiocytosis XWegeners granulomatosisRetinoblastomaChediak-Higashi syndrome  <response>: a. Histiocytosis XRef: Nelsons 20e p 2484-2489, Ghai 8e 620-621The given clinical picture prints to a diagnosis Langerhans cell; Histiocytosis of previously called Histiocytosis X. 