rosacea A chronic skin disease that causes persistent redness over the areas of the face and nose that normally blush: mainly the forehead, the chin, and the lower half of the nose. The tiny blood vessels in these areas enlarge (dilate) and become more visible through the skin, appearing like tiny red lines (telangiectasias). Pimples…
roseola See measles.
rotator cuff A group of four tendons that stabilize the shoulder joint. Each of these tendons attaches to a muscle that moves the shoulder in a specific direction. The four muscles whose tendons form the rotator cuff are the subscapularis muscle, which moves the arm by turning it inward (internal rotation); the supraspinatus muscle, which…
rotator cuff disease Damage to the rotator cuff that can be due to trauma, as from falling and injuring the shoulder; overuse in sports, particularly those that involve repetitive overhead motions; inflammation, as from tendonitis, bursitis, or arthritis of the shoulder; or degeneration, as from aging. The main symptom of rotator cuff disease is shoulder…
rotavirus A virus that is a leading cause of severe diarrhea and dehydration in young children. Abbreviated RV. Almost everyone catches RV before entering school, but, with rehydration and good nutrition, nearly all recover fully. Aside from causing acute infantile gastroenteritis and diarrhea in young children, RV is typically accompanied by lowgrade fever. Immunization of…
Rothmund-Thomson syndrome A hereditary disease that is characterized by progressive effects on multiple areas of the body, including the skin, hair, eyelashes, teeth, musculoskeletal system, blood, and eyes. Patients have an increased risk for developing cancer, especially osteosarcoma and skin cancer. Abbreviated RTS. RTS is inherited as an autosomal recessive trait and is caused by…
roundworm A type of parasitic worm that hatches in the intestines and lives there. The eggs of the roundworm usually enter the body through contaminated water or food or on fingers placed in the mouth after the hands have touched a contaminated object. Symptoms of roundworm infections include fatigue, weight loss, irritability, poor appetite, abdominal…
RPR test Rapid plasma reagin test. See syphilis test, RPR.
rRNA Ribosomal RNA. See RNA, ribosomal.
RSV 1 Respiratory syncytial virus. 2 Rous sarcoma virus, a virus that is the cause of a serious form of soft tissue cancer called sarcoma.
RTS Rothmund-Thomson syndrome.
ringworm of the nails See onychomycosis.