A rare chronic hematologic disorder characterized by the simultaneous or sequential association of autoimmune hemolytic anemia (AIHA; a disorder in which auto-antibodies are directed against red blood cells causing anemia of varying degrees of severity) with immune thrombocytopenic purpura (ITP; a coagulation disorder in which auto-antibodies are directed against platelets causing hemorrhagic episodes) and occasionally autoimmune neutropenia, in the absence of a known underlying etiology.
Hyperkeratosis is thickening of the outer layer of the skin, the stratum corneum, which is composed of large, polyhedral, plate-like envelopes filled with keratin which are the dead cells that have migrated up from the stratum granulosum.
From the differential diagnostic point of view, the mucosa hyperkeratosis syndrome has to be distinguished from the Jadassohn-Lewandowsky syndrome and the Howel-Evans' syndrome, which is associated with esophageal carcinoma.