Petechiae · What Is It, Causes, Treatment, and More

Petechiae are small, red or purple spots that occur as a result of bleeding into the skin or mucous membranes (i.e., the tissue lining various body cavities, including the mouth). In most cases, petechiae are caused by benign and harmless conditions, but sometimes, they may be a sign of an underlying disorder that requires urgent attention. Although petechiae can occur at any age, they are more commonly seen in older adults and children. 

Petechiae are caused by minor bleedings from capillaries, tiny blood vessels that lie under the skin and mucous membranes. Although many causes can lead to petechiae, the underlying mechanisms typically involve damage to the capillary walls, causing blood leakage, or a low blood platelet count (i.e., thrombocytopenia), which can lead to spontaneous bleeding in the absence of trauma. 

Tiny petechiae appearing on the face, neck, and upper chest are often caused by rupture of capillaries due to prolonged straining during a bowel movement or severe bouts of coughing or vomiting. Petechiae may also occur as a result of traumatic injuries, sunburns, or as a side effect of certain medications, such as antibiotics and anticonvulsants.  

In children, infections are a common cause of petechiae. Pathogens associated with petechiae include viruses, like cytomegalovirus (CMV), Epstein-Barr virus (EBV), or influenza; bacteria, including Neisseria meningitidis and group A Streptococcus species; and fungi, such as Candida and Aspergillus species. Other, less common infections that can lead to petechiae include Rocky Mountain spotted fever, which is transmitted by a tick bite, and viral hemorrhagic fevers, such as dengue, Ebola, and yellow fever. Overall, infections can lead to petechiae through several different mechanisms, including damage to the blood vessel walls, toxin release, or uncontrolled activation of the coagulation cascade, which in turn can lead to a low blood platelet count.

Petechiae appear as flat, red or purple spots that measure between 1 to 2 millimeters (about 0.04 to 0.08 inches) in diameter. On the other hand, when the spots are larger than 2 mm, but smaller than 1 centimeter (about a third of an inch), they are referred to as purpura. Lesions that are greater than 1 cm are called ecchymoses or bruises.  

Both petechiae and purpura are small types of bruises, caused by blood leaking into the skin and creating a visible spot. Characteristically, these spots are non-blanching, meaning they do not become paler when pressed lightly for a few seconds. This can be helpful to differentiate them from other skin lesions, such as allergic skin rashes or spider veins, which appear whitish when pressure is applied. 

Diagnosis of petechiae is based on the observation of non-blanching, pinpoint-sized, red or purple spots. Careful evaluation of any individual with petechiae is essential for early diagnosis and treatment of underlying conditions, particularly in children who appear unwell and present with signs of infection. In such cases, a very serious condition known as meningococcal sepsis, a widespread infection by Neisseria meningitidis, should be suspected and treated urgently.  

After a thorough medical history and physical exam, further assessment depends on the clinical suspicion and may include blood tests, microbiological cultures, or imaging techniques, such as X-ray or computerized tomography (CT) scan.  

Treatment of petechiae is aimed at resolving the underlying cause. In some cases, petechiae may fade away spontaneously, especially when caused by a mild viral infection or minor injury. If drug-induced, petechiae may resolve upon discontinuation of the specific medication.  On the other hand, if petechiae are a result of a bacterial infection, treatment may include broad-spectrum antibiotics, as well as supportive measures and, possibly, hospitalization. Finally, other causes of petechiae may require specific treatments or referral to other medical specialists in order to confirm the diagnosis and treat the underlying condition.