A petechia (/pɪˈtiːkiə/;[1]
pl.: petechiae) is a small red or purple spot (≤4 mm in diameter) that can appear on the
skin,
conjunctiva,
retina, and
mucous membranes which is caused by haemorrhage of capillaries.[2][3] The word is derived from Italian petecchia, 'freckle,' of obscure origin.[1] It refers to one of the three descriptive types of
hematoma differentiated by size, the other two being
ecchymosis (>1cm in diameter) and
purpura (4-10mm in diameter). The term is typically used in the plural (petechiae), since a single petechia is seldom noticed or significant.
Causes
Physical trauma
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. Excessive scratching and friction, especially on thin and poorly circulated parts of the body may also cause petechiae. Such instances are generally considered harmless and usually disappear within a few days, but depending on severity and frequency may be indicative of an underlying medical condition.
Constriction, asphyxiation – petechiae, especially in the eyes, may also occur when excessive pressure is applied to tissue (e.g., when a tourniquet is applied to an extremity or with excessive coughing or vomiting).
Thrombocytopenia – Low
platelet counts or diminished platelet function (e.g., as a side effect of medications or during certain infections) can give rise to petechial spots[6]
Sjögren syndrome – Petechial spots could occur due to
vasculitis, an inflammation of the blood vessels. In such a case immediate treatment is needed to prevent permanent damage. Some malignancies can also cause petechiae to appear.
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.[11] 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.
^Reyes, Melissa A.; Eichenfield, Lawrence F. (2012-01-01), Long, Sarah S. (ed.),
"73 - Purpura", Principles and Practice of Pediatric Infectious Diseases (Fourth Edition), London: Elsevier, pp. 441–444.e1,
ISBN978-1-4377-2702-9, retrieved 2022-08-02
^Fact Sheet: Tonsillitis from American Academy of Otolaryngology. "Updated 1/11". Retrieved November 2011
^Brook I, Dohar JE (December 2006). "Management of group A beta-hemolytic streptococcal pharyngotonsillitis in children". J Fam Pract. 55 (12): S1–11, quiz S12.
PMID17137534.