A petechia (; : 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. The word is derived from Italian , 'freckle,' of obscure origin. 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 always 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). Sunburn, childbirth, weightlifting Gua Sha, a Chinese treatment that scrapes the skin High-G training Hickey Asphyxiation Choking game Oral sex
Non-infectious conditions
Vitamin C deficiency, scurvy
Vitamin K deficiency
Leukemia
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 clotting factor deficiencies – (Von Willebrand disease) Hypocalcemia Idiopathic thrombocytopenic purpura Coeliac disease Aplastic anaemia Lupus Kwashiorkor or Marasmus – Childhood protein-energy malnutrition Erythroblastosis fetalis Henoch–Schönlein purpura Kawasaki disease Schamberg disease Ehlers–Danlos syndrome 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. Radiation Fat embolism syndrome
Infectious conditions
Babesiosis
Bolivian hemorrhagic fever
Boutonneuse fever
Chikungunya
Cerebral malaria
Congenital syphilis
Crimean–Congo hemorrhagic fever
Cytomegalovirus
Dengue fever
Dukes' disease
Ebola
Endocarditis
Influenza A virus subtype H1N1
Hantavirus
Infectious mononucleosis
Marburg virus
Neisseria meningitidis
Rocky Mountain spotted fever
Scarlet fever
Typhus
Streptococcal pharyngitis – Petechiae on the soft palate are mainly associated with streptococcal pharyngitis, and as such it is an uncommon but highly specific finding.
Forensic science
Petechiae on the face and conjunctiva (eyes) 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.