Oral hemorrhagic blister: an enigma.

Angina bullosa hemorrhagica (ABH) is a disorder of unclear aetiology characterized by abrupt and unprovoked presentation of blood-filled blister over the oral mucosa. Histopathology reveals sub epithelial blister containing erythrocytes with superficial perivascular lymphocytic infiltrate. We report two cases of ABH of which one was idiopathic and other was associated with chronic renal failure on hemodialysis.