Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «R»:
Rash: Breaking out (eruption) of the skin. Medically, a rash is referred to as an exanthem....
Rash, butterfly: A red, flat facial rash over the bridge of the nose. Over half of patients with systemic lupus erythematosus (SLE) develop this characteristic rash. Because of its shape, it is frequently referred to as the
"butterfly rash" of lupus.
The butterfly rash of lupus is typically painle...
Rash, chickenpox: Chickenpox is characterized by a rash, often the first sign of the disease. The rash of chickenpox develops in crops with raised red spots arriving first, progressing to blisters that burst, creating open sores, before crusting over. This process usually starts on the scalp, then t...
Rash, varicella: Varicella (chickenpox) is characterized by a rash, often the first sign of the disease. The rash of chickenpox develops in crops with raised red spots arriving first, progressing to blisters that burst, creating open sores, before crusting over. This process usually starts on the sc...
Rash, vesicular: A raised, blistery rash....
Rash, yeast diaper
Rash, yeast diaper: Infection in the diaper area caused by a yeast formerly called Monilia and now called Candida. These organisms are part of the germs normally found in various parts of the body and ordinarily do not cause any symptoms.
Certain conditions, such as antibiotic use or excessive mois...
Rasmussen encephalitis: A rare progressive neurological disorder that is characterized by intractable seizures and progressive neurologic deterioration. To be more precise, there are frequent and severe seizures (convulsions), progressive loss of motor skills and speech, hemiparesis (paralysis on on...
Rasmussen syndrome: A brain disorder caused
by inflammation of brain cells in one hemisphere. Its cause
is unknown. Rasmussen syndrome causes seizures often
difficult or impossible to control with medication, and
eventually results in brain shrinkage (atrophy). Treatment
is with surgery, if poss...
RAST: An allergy test done on a sample of blood. The
aim with RAST, as with skin tests, is to check for allergic sensitivity to specific
In the test, the sample of blood is mixed with substances known to trigger allergies. The test measures the level of allergy antibodies (specific IgE a...
Rat, cotton: See: Cotton rat....
Rat, rice: See: Rice rat....
Rat-flea typhus: Murine typhus, an acute infectious
disease with fever, headache, and rash, all quite similar to, but milder than, epidemic
typhus, caused by a related microorganism, Rickettsia typhi (mooseri), transmitted to
humans by rat fleas (Xenopsylla cheopis). The animal reservoir includes ra...
Rate, basal metabolic
Rate, basal metabolic: A measure of the rate of
metabolism. For example, someone with an overly active thyroid will have an elevated basal
Rate, birth: The birth rate is usually given as the
number of live births divided by the average population (or the population at midyear).
This is termed the crude birth rate. In 1995, for example, the crude birth rate per 1,000
population was 14 in the United States, 16.9 in Australia, etc.
The number of deaths in the population divided by the average population (or the population at midyear) is the crude death rate. In 1994, for example, the crude death rate per 1,000 population was 8.8 in the United States, 7.1 in Australia, etc. A death rate can also be tabulated accord...