A Guide to Clinical Differential Diagnosis of Oral Mucosal Lesions
Extravascular Blood Lesions

Course Author(s): Michael W. Finkelstein, DDS, MS; Emily Lanzel, DDS, MS; John W. Hellstein, DDS, MS

Extravascular Blood Lesions

Extravascular Blood Lesions are due to the presence of blood outside of blood vessels. They do not blanch and typically resolve within a month. The patient often has a history of trauma or bleeding problem.

Ecchymosis* is a bruise. It occurs due to hemorrhage and accumulation of blood in the connective tissue. It is usually the result of trauma, but may also be secondary to deficiency of platelets and/or clotting factors and viral infections. An ecchymosis is typically flat and red, purple, or blue in color. If the ecchymosis is due to trauma, then it will resolve spontaneously and no treatment is necessary. If it is secondary to a systemic disease, then further workup is indicated.

Image: Ecchymosis

A hematoma* is the result of hemorrhage, with pooling of blood in the connective tissue. A hematoma causes thickening or enlargement of the mucosa. It is purple to black in color. No treatment is necessary once a diagnosis is made. A hematoma will resolve spontaneously in several weeks to over a month.

Image: Hematoma

Petechiae* are round, red, pinpoint areas of hemorrhage. Petechiae are usually caused by trauma, viral infection, or a bleeding problem. They resolve over a few weeks. Petechiae do not require treatment. Investigation of the cause of petechiae may be indicated.

Image: Petechiae
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