Acute disseminated encephalomyelitis

Acute disseminated encephalomyelitis is a neurological condition characterized by a brief but intense attack of inflammation in the brain and spinal cord that damages myelin – the protective covering of nerve fibers. It often follows viral infection, or less often, vaccination for measles, mumps, or rubella. Treatment for ADEM is targeted at suppressing inflammation in the brain using anti-inflammatory drugs. Plasmapheresis or intravenous immunoglobulin therapy may also be used. Additional treatment is symptomatic and supportive.

Acute erythro leukemia

Acute erythroleukemia is a rare subtype of acute myeloid leukemia that has undergone several changes in classification over the past 30 years. There are two subtypes of acute erythroleukemia: the more common erythroid/myeloid subtype, defined by the presence of increased erythroid cells and myeloid blasts; and the rarer, pure erythroid subtype, characterized by expansion of immature erythroid cells only. The erythroid/myeloid subtype of acute erythroleukemia is closely related to acute myeloid leukemia with myelodysplasia-related changes, and is frequently characterized by morphological dysplasia and complex karyotype. Pure erythroleukemia is a very uncommon subtype of leukemia associated with a very poor response and survival to current available therapeutic agents.

Acute erythroblastic leukemia

Acute erythroid leukemia or Di Guglielmo syndrome is a rare form of acute myeloid leukemia (less than 5% of AML cases where the myeloproliferation is of erythroblastic precursors. It is defined as type "M6" under the FAB classification. M6 or erythroleukemia is rare and difficult to diagnose. More than 30-50% of the nucleated marrow cells are abnormal nucleated red blood cells.

Erythroleukemia is predominantly a disease of adults. It comprises 5-6% of cases of AML. Pure erythroid leukemiais extremely rare and can occur at any age. Occasional cases of CML will transform in to AML-M6.

Acute fatty liver of pregnancy

Acute fatty liver of pregnancy is a rare and serious complication of pregnancy. It is characterized by a build-up of fat in the liver, which can lead to liver damage. It can be fatal without prompt diagnosis and treatment which involves delivering the baby as soon as possible. the cause of AFLP is not well understood, but genetics may play a role. The possible explanation is that a disordered metabolism of fatty acids by mitochondria in the mother, caused by long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency.  The condition was previously thought to be universally fatal, but aggressive treatment by stabilizing the mother with intravenous fluids and blood products in anticipation of early delivery has improved prognosis.

Acute hemorrhagic leukoencephalitis

Acute hemorrhagic leukoencephalitis  is a very rare form of acute disseminated encephalomyelitis that usually results in death. It is characterized by a brief but intense attack of inflammation in the brain and spinal cord that damages the myelin -- the protective covering of the nerve fibers. It may also cause bleeding in the brain, leading to damage of the white matter.

Acute intermittent porphyria

Acute intermittent porphyria is one of the liver (hepatic) porphyrias. AIP is caused by low levels of porphobilinogen deaminase (PBGD), an enzyme also often called hydroxymethylbilane synthase. The low levels of PBGD are generally not sufficient to cause symptoms; however, activating factors such as hormones, drugs, and dietary changes may trigger symptoms. Although most individuals with AIP never develop symptoms, symptomatic individuals typically present with abdominal pain with nausea. Treatment is dependent on the symptoms.

Acute Lung Injury (ALI)

Acute lung injury (ALI) or acute respiratory distress syndrome (ARDS), is a lung condition that leads to low oxygen levels in the blood. ARDS can be life threatening. This is because your body's organs, such as the kidneys and brain, need oxygen-rich blood to work properly.

ARDS usually occurs in people who are very ill with another disease or who have major injuries. Most people are already in the hospital when they develop ARDS.

To understand ARDS, it helps to understand how the lungs work. When you breathe, air passes through your nose and mouth into your windpipe. The air then travels to your lungs' air sacs. These sacs are called alveoli.

Small blood vessels called capillaries run through the walls of the air sacs. Oxygen passes from the air sacs into the capillaries and then into the bloodstream. Blood carries the oxygen to all parts of the body, including the body's organs.

In ARDS, infections, injuries, or other conditions cause the lung's capillaries to leak more fluid than normal into the air sacs. This prevents the lungs from filling with air and moving enough oxygen into the bloodstream.

When this happens, the body's organs don't get the oxygen they need. Without oxygen, the organs may not work properly or may stop working completely.

Most people who develop ARDS are in the hospital for other serious health problems. Rarely, people who aren't hospitalized have health problems that lead to ARDS, such as severe pneumonia.


Source: The National Heart, Lung, and Blood Institute (NHLBI)

Acute lymphoblastic leukemia

Acute lymphoblastic leukemia is an acute form of leukemia, or cancer of the white blood cells, characterized by the overproduction and accumulation of cancerous, immature white blood cells, known as lymphoblasts. In persons with ALL, lymphoblasts are overproduced in the bone marrow and continuously multiply, causing damage and death by inhibiting the production of normal cells (such as red and white blood cells and platelets) in the bone marrow and by spreading (infiltrating) to other organs. ALL is most common in childhood, with a peak incidence at 2–5 years of age and another peak in old age.

About 6,000 cases are reported in the United States every year. Internationally, ALL is more common in Caucasians than in Africa; it is more common in Hispanics and in Latin America. Cure is a realistic goal and is achieved in more than 80% of affected children, although only 20-40% of adults are cured. "Acute" refers to the relatively short time course of the disease, distinguishing it from chronic lymphocytic leukemia, which has a potential time course of many years.

Acute lymphoblastic leukemia congenital sporadic aniridia

Acute lymphoblastic leukemia congenital sporadic aniridia is a rare association between a particular leukemia and congenital aniridia. Leukemia is a cancer of the blood. Congenital aniridia is the underdevelopment or absence of part of the outer eye called the iris (the colored part of the eye).

Acute megakaryoblastic leukemia

Acute megacaryoblastic leukemia (AMKL) is a rare form of malignant bone marrow cancer involving the proliferation of immature precursors of blood cells. More specifically, it involves the rapid proliferation of megakaryoblasts (premature form of megakaryocytes).

It is classified under M7 in the French-American-British classification.

Acute monoblastic leukemia

Acute monocytic leukemia is considered a type of acute myeloid leukemia.. Acute myeloblastic leukemia type 5 is a rare form of malignant bone marrow cancer involving the proliferation of immature precursors of blood cells. Type 5 involves the rapid proliferation of monoblasts (immature precursors of monocytes) in particular.

Acute mountain sickness

Acute mountain sickness is a pathological effect of high altitude on humans, caused by acute exposure to low partial pressure of oxygen at high altitude. It commonly occurs above 2,400 metres (8,000 feet). It presents as a collection of nonspecific symptoms, acquired at high altitude or in low air pressure, resembling a case of "flu, carbon monoxide poisoning, or a hangover". It is hard to determine who will be affected by altitude sickness, as there are no specific factors that correlate with a susceptibility to altitude sickness. However, most people can ascend to 2,400 metres (8,000 ft) without difficulty.

Acute mountain sickness can progress to high altitude pulmonary edema (HAPE) or high altitude cerebral edema (HACE), which are potentially fatal.

Chronic mountain sickness, also known as Monge's disease, is a different condition that only occurs after very prolonged exposure to high altitude.

Acute myelocytic leukemia

Acute myelocytic leukemia is a cancer of the blood-forming tissues of the bone marrow involving the proliferation of cells that normally develop into infection-fighting cells such as eosinophils, monocytes, basophils and neutrophils. The cancerous cells replace the normal bone marrow cells. Acute leukemia involves a more rapid proliferation of cancer cells compared to chronic forms of leukemia.

Acute myeloid leukemia

Acute myeloid leukemia (AML) is a cancer that affects the blood and bone marrow. Conditions are generally called "acute" when they develop quickly and have an aggressive course. The signs and symptoms of AML vary but may include easy bruising; bone pain or tenderness; fatigue; fever; frequent nosebleeds; bleeding from the gums; shortness of breath; and/or weightloss. AML is one of the most common types of leukemia among adults and is rarely diagnosed in people under age 40. There are many potential causes of AML such as certain blood disorders, inherited syndromes, environmental exposures, and drug exposures; however, most people who develop AML have no identifiable risk factor. Treatment may include a combination of chemotherapyradiation therapybone marrow transplant and/or other drug therapy.

Acute myelomonocytic leukemia

Acute myelomonocytic leukemia is a form of acute myeloid leukemia which involves a proliferation of CFU-GM myeloblasts and monoblasts. Progression from myelodysplastic syndrome has been reported.

It is classified under "M4" in the French-American-British classification (FAB).

It is classified under "AML, not otherwise classified" in the WHO classification.

Translocations have been observed.

Acute necrotizing ulcerative gingivitis

Acute necrotizing ulcerative gingivitis is a common, non-contagious infection of the gums with sudden onset. The main features are painful, bleeding gums, and ulceration of inter-dental papillae (the sections of gum between adjacent teeth). This disease, along with necrotizing (ulcerative) periodontitis (NP or NUP) is classified as a necrotizing periodontal disease, one of the seven general types of periodontitis. The often severe gingival pain that characterizes ANUG distinguishes it from the more common chronic periodontitis which is rarely painful. ANUG is the acute presentation of necrotizing ulcerative gingivitis (NUG), which is the usual course the disease takes. If improperly treated or neglected, NUG may become chronic and/or recurrent. The causative organisms are mostly anaerobic bacteria, particularly Fusobacteria and Spirocaete species. Predisposing factors include poor oral hygiene, smoking, malnutrition, psychological stress and immunosuppression (sub-optimal functioning of the immune system). When the attachments of the teeth to the bone are involved, the term NUP is used. Treatment of ANUG is by debridement (although pain may prevent this) and antibiotics (usually metronidazole) in the acute phase, and improving oral hygiene to prevent recurrence. Although the condition has a rapid onset and is debilitating, it usually resolves quickly and does no serious harm. The synonym "trench mouth" arose during World War I as many soldiers developed the disease, probably because of the poor conditions and extreme psychological stress.

Acute non lymphoblastic leukemia (generic term)

A form of rapidly progressing blood cancer resulting in the rapid proliferation of granulocytes and monocytes, red blood cells and platelets. It is one of the most common forms of leukemia in adults but can occur in children.

Acute posterior multifocal placoid pigment epitheliopathy

Acute posterior multifocal placoid pigment epitheliopathy is an acquired, inflammatory eye condition affecting the retina, retinal pigment epithelium (pigmented layer of the retina), and choroid. It usually affects both eyes and is characterized by multiple, yellow-white lesions in the back of the eye. The condition can significantly impair visual acuity if the macula is involved. APMPPE typically resolves on its own in weeks to months. While the cause is unknown, about a third of cases appear to develop after a flu-like illness. Non-ocular symptoms are uncommon, but cerebral vasculitis can be present and may cause permanent and/or severe neurological complications.

It occurs more commonly in females, and is more likely to affect a persons between 20–30 years of ages but has been seen in people 16 to 40 years of age . It is known to occur after or concurrently with a systemic infection (but not always), showing that it is related generally to an altered immune system. Recurrent episodes can happen, but is extremely rare.

Acute promyelocytic leukemia

Acute promyelocytic leukaemia is an aggressive type of acute myeloid leukemia in which there are too many immature blood-forming cells in the blood and bone marrow. It is usually marked by a translocation of chromosomes 15 and 17. Acute promyelocytic leukemia usually occurs in middle-aged adults. Symptoms may include both bleeding and forming blood clots.

Leukaemia is a cancer of the blood. It affects the white blood cells, which are important part of our immune system that fights infection. There are four main types of leukaemia: 1) acute myeloid leukaemia (AML), 2) acute lymphoblastic leukaemia (ALL), 3) chronic myeloid leukaemia (CML) and 4) chronic lymphocytic leukaemia (CLL).

Acute radiation syndrome

Acute Radiation Syndrome (ARS) (sometimes known as radiation toxicity or radiation sickness) is an acute illness caused by irradiation of the entire body (or most of the body) by a high dose of penetrating radiation in a very short period of time (usually a matter of minutes).

The three classic ARS Syndromes are:

Bone marrow syndrome (sometimes referred to as hematopoietic syndrome): The survival rate of patients with this syndrome decreases with increasing dose. The primary cause of death is the destruction of the bone marrow, resulting in infection and hemorrhage.

Gastrointestinal (GI) syndrome: Survival is extremely unlikely with this syndrome. Destructive and irreparable changes in the GI tract and bone marrow usually cause infection, dehydration, and electrolyte imbalance. Death usually occurs within 2 weeks. Damage to the gastrointestinal tract is one of the primary causes of morbidity and mortality following radiation exposure.

Cardiovascular (CV)/ Central Nervous System (CNS) syndrome: Death occurs within 3 days. Death likely is due to collapse of the circulatory system as well as increased pressure in the confining cranial vault as the result of increased fluid content caused by edema, vasculitis, and meningitis.

Acute respiratory distress syndrome

Acute respiratory distress syndrome is a life-threatening lung condition that prevents enough oxygen from getting to the lungs and into the blood.  People who develop ARDS often are very ill with another disease or have major injuries. The condition leads to a buildup of fluid in the air sacs which prevents enough oxygen from passing into the bloodstream.

ARDS is not a particular disease, rather it is a clinical phenotype which may be triggered by various pathologies such as trauma, pneumonia and sepsis. The hallmark of ARDS is diffuse injury to cells which form the alveolar barrier, surfactant dysfunction, activation of the innate immune response, and abnormal coagulation. In effect, ARDS results in impaired gas exchange within the lungs at the level of the microscopic alveoli.

The syndrome is associated with a high mortality rate between 20 and 50%. The mortality rate with ARDS varies widely based on severity, the patient's age, and the presence of other underlying medical conditions.

Although the terminology of "adult respiratory distress syndrome" has at times been used to differentiate ARDS from "infant respiratory distress syndrome" in neonates, international consensus is that "acute respiratory distress syndrome" is the best moniker because ARDS can affect those of all ages.

Acute zonal occult outer retinopathy

Acute zonal occult outer retinopathy is a rare condition that affects the eyes. People with this condition may experience a sudden onset of photopsia (the presence of perceived flashes of light) and an area of partial vision loss (a blindspot). Other symptoms may include "whitening of vision" or blurred vision. Although anyone can be affected, the condition is most commonly diagnosed in young women (average age 36.7 years). 

Adactylia unilateral dominant

A rare genetic condition characterized by missing portions of fingers usually with some sort of malformed remnant of a nail on the end of what is remaining of the finger.

Adams Nance syndrome

Adams Nance syndrome is a medical condition consisting of persistent tachycardia, paroxymal hypertension and seizures. It is associated with hyperglycinuria, dominantly inherited microphthalmia and cataracts. It is thought to be caused by a disturbance in glycine metabolism.

Adams Oliver syndrome

Adams-Oliver syndrome is a rare condition that is present at birth. The primary features are an abnormality in skin development (called aplasia cutis congenita) and malformations of the limbs. A variety of other features can occur in people with Adams-Oliver syndrome.
Most people with Adams-Oliver syndrome have aplasia cutis congenita, a condition characterized by localized areas of missing skin typically occurring on the top of the head (the skull vertex). In some cases, the bone under the skin is also underdeveloped. Individuals with this condition commonly have scarring and an absence of hair growth in the affected area.

Abnormalities of the hands and feet are also common in people with Adams-Oliver syndrome. These most often involve the fingers and toes and can include abnormal nails, fingers or toes that are fused together (syndactyly), and abnormally short or missing fingers or toes (brachydactyly or oligodactyly). In some cases, other bones in the hands, feet, or lower limbs are malformed or missing.
Some affected infants have a condition called cutis marmorata telangiectatica congenita. This disorder of the blood vessels causes a reddish or purplish net-like pattern on the skin. In addition, people with Adams-Oliver syndrome can develop high blood pressure in the blood vessels between the heart and the lungs (pulmonary hypertension), which can be life-threatening. Other blood vessel problems and heart defects can occur in affected individuals.

In some cases, people with Adams-Oliver syndrome have neurological problems, such as developmental delay, learning disabilities, or abnormalities in the structure of the brain.

Addison’s disease

Addison’s disease is a rare, chronic endocrine system disorder in which the adrenal glands do not produce sufficient steroid hormones (glucocorticoids and mineralocorticoids). It is characterised by a number of relatively nonspecific symptoms, such as abdominal pain and weakness, but under certain circumstances, these may progress to Addisonian crisis, a severe illness which may include very low blood pressure and coma.

The condition arises from problems with the adrenal gland, primary adrenal insufficiency, and can be caused by damage by the body's own immune system, certain infections, or various rarer causes. Addison's disease is also known as chronic primary adrenocortical insufficiency, to distinguish it from acute primary adrenocortical insufficiency, most often caused by Waterhouse–Friderichsen syndrome. Addison's disease should also be distinguished from secondary and tertiary adrenal insufficiency, which are caused by deficiency of ACTH (produced by the pituitary gland) and CRH (produced by the hypothalamus), respectively. Despite this distinction, Addisonian crises can happen in all forms of adrenal insufficiency.

Adducted thumb and clubfoot syndrome

Adducted thumb and clubfoot syndrome is an autosomal recessive connective tissue disorder characterized by congenital malformations, contractures of thumbs and feet, a typical facial appearance, and normal cognitive development. It is also characterized by a thumb abnormality as well as mental retardation, foot defects and other anomalies. This condition is caused by mutations in the CHST14 gene.

Adducted thumb syndrome recessive form

Adducted thumb syndrome recessive form, also known as Christian syndrome or Craniostenosis arthrogryposis cleft palate, is a rare disease affecting multiple systems which causes malformations of the palate, thumbs, and upper limbs.  It is an autosomal recessive connective tissue disorder characterized by congenital malformations, contractures of the thumb and feet, a typical facial appearance, and normal cognitive development. This is caused by mutation in the CHST14 (CARBOHYDRATE SULFOTRANSFERASE 14) gene.

Adenine phosphoribosyltransferase deficiency

Purines are key components of cellular energy systems (eg, ATP, NAD) signaling (eg, GTP, cAMP, cGMP) and along with pyrimidines, RNA and DNA production. Purines and pyrimidines may be synthesized de novo or recycled by a salvage pathway from normal catabolism. The end product of complete catabolism of purines is uric acid; catabolism of pyrimidines produces citric acid cycle intermediates.