Petechia


A petechia is a small red or purple spot on the skin or conjunctiva, caused by a minor bleed from broken capillary blood vessels. The word is derived from Latin 'petigo', meaning ‘scab' or 'eruption’.
Petechia refers to one of the three descriptive types of hematoma differentiated by size, the other two being ecchymosis and purpura. Ecchymosis is defined as hematomas larger than 1 centimetre and purpura as 1–5 millimetres.
The term is almost always used in the plural, since a single lesion is seldom noticed or significant.

Causes

Physical trauma

Coughing, holding breath, vomiting, crying – The most common cause of petechiae is through physical trauma such as a hard bout of coughing, holding breath, vomiting, or crying, which can result in facial petechiae, especially around the eyes. Such instances are harmless and usually disappear within a few days.
Petechiae on the face and conjunctiva are unrelated to asphyxiation or hypoxia.
Despite this, petechiae are used by police investigators in determining whether strangulation has been part of an attack. The documentation of the presence of petechiae on a victim can help police investigators prove the case. Petechiae resulting from strangulation can be relatively tiny and light in color to very bright and pronounced. Petechiae may be seen on the face, in the whites of the eyes or on the inside of the eyelids.