Occurring upon occasion or in a scattered, isolated, or seemingly random way.
An infection caused by the fungus Sporothrix schenckii, typically involving the skin. Persons handling thorny plants, sphagnum moss, or baled hay are at increased risk of developing sporotrichosis. The first sign is usually a small painless bump resembling an insect bite. The bump can be red, pink, or purple in color, and it usually appears […]
- Spot, blind
A small area of the retina where the optic nerve enters the eye; this type of blind spot occurs normally in all eyes. Any gap in the visual field corresponding to an area of the retina where no visual cells are present; this type of blind spot is associated with eye disease.
- Spots in front of the eyes
Also known as “floaters”, blurry spots that drift in front of the eyes but do not block vision. The blur is the result of debris from the vitreous casting a shadow on the retina. The spot is the image formed by a deposit of protein drifting about in the vitreous, the clear jelly-like substance that […]
- Spots, Brushfield's
Speckled iris. Little white spots that slightly elevated on the surface of the iris and are arranged in a ring concentric with the pupil. These spots occur in normal children but are far more frequent in Down’s syndrome (trisomy 21). They were described in 1924 by Thomas Brushfield and are due to aggregation of a […]
- Spotted fever
Also known as Rocky Mountain spotted fever. An acute febrile (feverish) disease initially recognized in the Rocky Mountain states, caused by Rickettsia rickettsii transmitted by hard-shelled (ixodid) ticks. Occurs only in the Western Hemisphere. Anyone frequenting tick-infested areas is at risk for RMSF. The onset of symptoms is abrupt with headache, high fever, chills, muscle […]