Diseases

Rheumatic Fever

Rheumatic fever (also known as acute rheumatic fever, ARF), is an inflammatory disease that can involve the heart, joints, skin, and brain. The disease typically develops two to four weeks after a throat infection. Signs and symptoms include fever, multiple painful joints, involuntary muscle movements, and a characteristic but uncommon non itchy rash known as erythema marginatum. The heart is involved in about half of cases. Permanent damage to the heart valves, known as rheumatic heart disease (RHD), usually only occurs after multiple attacks but may occasionally occur after a single case of ARF. The damaged valves may result in heart failure. The abnormal valves also increase the risk of the person developing atrial fibrillation and infection of the valves.

Acute rheumatic fever may occur following an infection of the throat by the bacteria Streptococcus pyogenes. If it is untreated ARF occurs in up to three percent of people. The underlying mechanism is believed to involve the production of antibodies against a person's own tissues. Some people due to their genetics are more likely to get the disease when exposed to the bacteria than others. Other risk factors include malnutrition and poverty. Diagnosis of ARF is often based on the presence of signs and symptoms in combination with evidence of a recent streptococcal infection.

Treating people who have strep throat with antibiotics, such as penicillin, decreases their risk of getting ARF. This often involves testing people with sore throats for the infection, which may not be available in the developing world. Other preventative measures include improved sanitation. In those with ARF and RHD prolonged periods of antibiotics are sometimes recommended. Gradual return to normal activities may occur following an attack. Once RHD develops, treatment is more difficult. Occasionally valve replacement surgery or repair is required. Otherwise complications are treated as per normal.

Acute rheumatic fever occurs in about 325,000 children each year and about 18 million people currently have rheumatic heart disease. Those who get ARF are most often between the ages of 5 and 14, with 20% of first-time attacks occurring in adults. The disease is most common in the developing world and among indigenous peoples in the developed world. In 2013 it resulted in 275,000 deaths down from 374,000 deaths in 1990. Most deaths occur in the developing world where as many as 12.5% of people affected may die each year. Descriptions of the condition are believed to date back to at least the 5th century BCE in the writings of Hippocrates. The disease is so named because its symptoms are similar to those of some rheumatic disorders

Rheumatoid nodulosis

A variant form of rheumatoid disease involving the development of nodules under the skin. Normally there is little or no joint pain involved. The nodules tend to form around joints such as the elbows.

Rheumatoid vasculitis

Vasculitis is a condition in which blood vessels become inflamed. When blood vessels become inflamed, they may become weakened, become thickened and increase in size, or become narrowed, sometimes to the point of stopping blood flow. The blood vessels most often involved are arteries which bring blood to the skin, nerves and internal organs. Small veins can also be involved. If inflammation is severe, tissues that are nourished by the blood vessel can be damaged when blood flow decreases. Because large blood vessels nourish larger quantities of tissue, the larger the involved vessel, the more likely serious tissue damage may occur. For this reason, the size of the blood vessel involved influences the amount of damage from rheumatoid vasculitis.

Rhizomelic chondrodysplasia punctata- type 2

A rare genetic disorder involving abnormal development of bones due to a particular enzyme deficiency (glyceronephosphate O-Acyl transferase). The bones have abnormal calcification of bones near the joints. The genetic defect is located on chromosome 1q42.

Rhizomelic chondrodysplasia punctata- type 3

A rare genetic disorder involving abnormal development of bones due to a particular enzyme deficiency (alkyldihydroxyacetonephosphate synthase). The bones have abnormal calcification of bones near the joints. The genetic defect is located on chromosome 2q31.

Rhizomelic syndrome

A very rare syndrome characterized mainly by short upper arm and thigh bones. Death frequently occurs in early childhood.

RHYNS syndrome

A rare syndrome characterized by eye, kidney and skeletal abnormalities as well as hypopituitarism.

Ribbing disease

A rare disorder primarily involving abnormal development of bone tissue inside parts of some long bones - particularly in the lower legs.

Richards-Rundle syndrome

A very rare syndrome characterized mainly by mental retardation, ataxia, deafness and ketoaciduria.

Richieri Costa Orquizas syndrome

A very rare syndrome characterized by a cleft palate, genital anomalies, retarded growth, heart defect and a hand abnormality.

Richieri Costa Pereira syndrome

A very rare syndrome characterized mainly by short stature, hand anomaly, clubfoot a cleft palate and various other abnormalities.

Richieri-Costa Colletto Otto syndrome

Richieri costa colletto otto syndrome (medical condition): A rare genetic disorder characterized by short stature, short fingers and toes and facial anomalies

Richter syndrome

A rare but serious form of acute adult leukemia. The disease occurs when chronic lymphocytic leukemia transforms into diffuse large cell lymphoma which is a fast-growing form of lymphoma. The condition tends to be more common in older adults.

Rickets

Rickets is a softening of bones in children potentially leading to fractures and deformity. Rickets is among the most frequent childhood diseases in many developing countries. The predominant cause is a vitamin D deficiency, but lack of adequate calcium in the diet may also lead to rickets (cases of severe diarrhoea and vomiting may be the cause of the deficiency). Although it can occur in adults, the majority of cases occur in children suffering from severe malnutrition, usually resulting from famine or starvation during the early stages of childhood. Osteomalacia is the term used to describe a similar condition occurring in adults, generally due to a deficiency of vitamin D. The origin of the word "rickets" is probably from the Old English dialect word 'wrickken', to twist. The Greek derived word "rachitis" (meaning "inflammation of the spine") was later adopted as the scientific term for rickets, due chiefly to the words' similarity in sound. In many languages it is known as "English disease".

Rickettsial disease

Rickettsia is a genus of motile, Gram-negative, non-sporeforming, highly pleomorphic bacteria that can present as cocci (0.1 μm in diameter), rods (1-4 μm long) or thread-like (10 μm long). Obligate intracellular parasites, the Rickettsia depend on entry, growth, and replication within the cytoplasm of eukaryotic host cells (typically endothelial cells). Because of this, Rickettsia cannot live in artificial nutrient environments and are grown either in tissue or embryo cultures (typically, chicken embryos are used). In the past they were regarded as microorganisms positioned somewhere between viruses and true bacteria. The majority of Rickettsia bacteria are susceptible to antibiotics of the tetracycline group. Rickettsia species are carried as parasites by many ticks, fleas, and lice, and cause diseases such as typhus, rickettsialpox, Boutonneuse fever, African Tick Bite Fever, Rocky Mountain spotted fever, Australian Tick Typhus, Flinders Island Spotted Fever and Queensland Tick Typhus [2] in human beings. They have also been associated with a range of plant diseases. Like viruses, they only grow inside living cells. The name rickettsia is often used for any member of the Rickettsiales. They are thought to be the closest living relatives to bacteria that were the origin of the mitochondria organelle that exists inside most eukaryotic cells.

Rickettsiosis

A disease caused by infection with rickettsial bacteria which are transmitted by arthropods such as ticks, mites and lice. Different rickettsial bacteria can cause different types of infections such as typhus, spotted fever and trench fever. Symptoms can vary somewhat between the different types.

Rieger syndrome

A rare genetic disorder characterized by underdeveloped or absent teeth and craniofacial and eye abnormalities.

Specialists recognize two genetic forms of Rieger syndrome. Type I occurs as a result of mutations on chromosome 4 and Type II results from mutations on chromosome 13.

Rieger syndrome 2

A rare disorder where abnormal development of the front portion of the eye causes glaucoma and impaired vision. Other abnormalities are also present.

Right ventricle hypoplasia

An underdeveloped right heart ventricle which is smaller than normal and is thus less able to pump blood efficiently to the lungs. The age at which the symptoms become apparent varies depending on the severity of the defect.

Rigid spine syndrome

A muscle wasting disorder mainly involving the muscles in the arms, legs, face, neck, spine and heart. Symptoms generally only occur in males but female carriers may have some symptoms.

Ring chromosome 14 syndrome

Ring chromosome 14 syndrome (ring 14, ring 14 syndrome, ring chromosome 14) is a very rare human chromosome abnormality. It occurs when one or both of the telomeres that mark the ends of chromosome 14 are lost allowing the now uncapped ends to fuse together forming a ring chromosome. It causes a number of serious health issues, most notably recurrent treatment-resistant seizures and intellectual disability.