Angina bullosa hemorrhagica: an unusual problem following periodontal therapy.

Angina bullosa hemorrhagica (ABH) describes benign subepithelial oral blood blisters not attributable to a systemic disorder. Little is known about the pathogenesis of ABH, although most cases have been associated with mild trauma prior to appearance of the lesion. This report discusses the clinical and histopathologic features of ABH which appeared after routine scaling and root planing.