Waterhouse–Friderichsen syndrome (WFS) is defined as adrenal gland failure due to bleeding into the adrenal glands, commonly caused by severe bacterial infection. Typically, it is caused by Neisseria meningitidis.
Vasculitis is a group of disorders that destroy blood vessels by inflammation. Both arteries and veins are affected. Lymphangitis is sometimes considered a type of vasculitis. Vasculitis is primarily caused by leukocyte migration and resultant damage. Although both occur in vasculitis, inflammation of veins (phlebitis) or arteries (arteritis) on their own are separate entities.
Henoch–Schönlein purpura (HSP), also known as IgA vasculitis, is a disease of the skin, mucous membranes, and sometimes other organs that most commonly affects children. In the skin, the disease causes palpable purpura, often with joint pain and abdominal pain. With kidney involvement, there may be a loss of small amounts of blood and protein in the urine, but this usually goes unnoticed; in a small proportion of cases, the kidney involvement proceeds to chronic kidney disease. HSP is often preceded by an infection, such as a throat infection.
Polyarteritis nodosa (PAN) is a systemic necrotizing inflammation of blood vessels (vasculitis) affecting medium-sized muscular arteries, typically involving the arteries of the kidneys and other internal organs but generally sparing the lungs' circulation. Small aneurysms are strung like the beads of a rosary, therefore making this "rosary sign" an important diagnostic feature of the vasculitis. PAN is sometimes associated with infection by the hepatitis B or hepatitis C virus. The condition may be present in infants.
Purpura is a condition of red or purple discolored spots on the skin that do not blanch on applying pressure. The spots are caused by bleeding underneath the skin secondary to platelet disorders, vascular disorders, coagulation disorders, or other causes. They measure 3–10 mm, whereas petechiae measure less than 3 mm, and ecchymoses greater than 1 cm.
A petechia is a small red or purple spot that can appear on the skin, conjunctiva, retina, and mucous membranes which is caused by haemorrhage of capillaries. The word is derived from Italian petecchia, 'freckle,' of obscure origin. It refers to one of the three descriptive types of hematoma differentiated by size, the other two being ecchymosis and purpura. The term is always used in the plural (petechiae), since a single petechia is seldom noticed or significant.
Cryoglobulinemia is a medical condition in which the blood contains large amounts of pathological cold sensitive antibodies called cryoglobulins – proteins that become insoluble at reduced temperatures. This should be contrasted with cold agglutinins, which cause agglutination of red blood cells.
Livedo reticularis is a common skin finding consisting of a mottled reticulated vascular pattern that appears as a lace-like purplish discoloration of the skin. The discoloration is caused by reduction in blood flow through the arterioles that supply the cutaneous capillaries, resulting in deoxygenated blood showing as blue discoloration. This can be a secondary effect of a condition that increases a person's risk of forming blood clots, including a wide array of pathological and nonpathological conditions. Examples include hyperlipidemia, microvascular hematological or anemia states, nutritional deficiencies, hyper- and autoimmune diseases, and drugs/toxins.
Gingivostomatitis is a combination of gingivitis and stomatitis, or an inflammation of the oral mucosa and gingiva. Herpetic gingivostomatitis is often the initial presentation during the first ("primary") herpes simplex infection. It is of greater severity than herpes labialis which is often the subsequent presentations. Primary herpetic gingivostomatitis is the most common viral infection of the mouth.
Gianotti–Crosti syndrome, also known as infantile papular acrodermatitis, papular acrodermatitis of childhood, and papulovesicular acrolocated syndrome, is a reaction of the skin to a viral infection. Hepatitis B virus and Epstein–Barr virus are the most frequently reported pathogens. Other viruses implicated are hepatitis A virus, hepatitis C virus, cytomegalovirus, coxsackievirus, adenovirus, enterovirus, rotavirus, rubella virus, HIV, and parainfluenza virus.
Necrotizing vasculitis, also called systemic necrotizing vasculitis, is a general term for the inflammation of veins and arteries that develops into necrosis and narrows the vessels.
Cryofibrinogenemia refers to a condition classified as a fibrinogen disorder in which a person's blood plasma is allowed to cool substantially, causing the (reversible) precipitation of a complex containing fibrinogen, fibrin, fibronectin, and, occasionally, small amounts of fibrin split products, albumin, immunoglobulins and other plasma proteins.
Cutaneous small-vessel vasculitis (CSVV), is inflammation of small blood vessels, usually accompanied by small lumps beneath the skin. The condition is also known as hypersensitivity vasculitis, cutaneous leukocytoclastic vasculitis, hypersensitivity angiitis, cutaneous leukocytoclastic angiitis, cutaneous necrotizing vasculitis and cutaneous necrotizing venulitis,
Acute hemorrhagic edema of infancy (AHEI) is a type of leukocytoclastic vasculitis that is not fatal. Although it causes fever, large palpable purpuric skin lesions, and edema, it is a harmless condition. AHEI's appearance is frequently similar to that of Henoch-Schönlein purpura. Because AHEI is a self-limiting disease, conservative treatment is common.
Cryoglobulinemic vasculitis is a form of inflammation affecting the blood vessels caused by the deposition of abnormal proteins called cryoglobulins. These immunoglobulin proteins are soluble at normal body temperatures, but become insoluble below 37 °C (98.6 °F) and subsequently may aggregate within smaller blood vessels. Inflammation within these obstructed blood vessels is due to the deposition of complement proteins which activate inflammatory pathways.
Necrolytic acral erythema is a cutaneous condition that is a manifestation of hepatitis C viral infection or zinc deficiency. In the early stages, bullae, erosions, and erythematous or violaceous papules are its defining characteristics. Well-defined plaques with erythema on the outer rim, lichenification, secondary hyperpigmentation, and fine desquamation on the surface begin to appear in the late phase.
Lupus vasculitis is one of the secondary vasculitides that occurs in approximately 50% of patients with systemic lupus erythematosus (SLE).
Cutaneous manifestations of COVID-19 are characteristic signs or symptoms of the Coronavirus disease 2019 that occur in the skin. The American Academy of Dermatology reports that skin lesions such as morbilliform, pernio, urticaria, macular erythema, vesicular purpura, papulosquamous purpura and retiform purpura are seen in people with COVID-19. Pernio-like lesions were more common in mild disease while retiform purpura was seen only in critically ill patients. The major dermatologic patterns identified in individuals with COVID-19 are urticarial rash, confluent erythematous/morbilliform rash, papulovesicular exanthem, chilbain-like acral pattern, livedo reticularis and purpuric "vasculitic" pattern. Chilblains and Multisystem inflammatory syndrome in children are also cutaneous manifestations of COVID-19.
Retiform purpura is the result of total vascular blockage and damage to the skin's blood vessels. The skin then shows lesions, appearing due to intravascular issues where clots, proteins, or emboli block skin vessels. They can also result from direct harm to the vessel walls, as seen in conditions like vasculitis, calciphylaxis, and certain severe opportunistic infections.
