Seckel syndrome A rare inherited form of dwarfism and growth delay. Other symptoms and features associated with Seckel syndrome include an abnormally small head (microcephaly); varying degrees of mental retardation; and/or unusual characteristic facial features including “beak-like” protrusion of the nose. The syndrome is inherited in an autosomal recessive manner and can be due to…
sebum An oily secretion of the sebaceous glands that helps to preserve the flexibility of the hair and retain moisture in the skin. Sebum is also secreted by the Meibomian glands of the eyes. See also gland, Meibomian.
seborrhea See dandruff.
seasonal affective disorder Depression that tends to occur (and recur) during a particular time of year, most often as the days grow shorter in the fall and winter. Abbreviated SAD. Affected persons may react adversely to decreasing amounts of light or colder temperatures, which affect the production of neurotransmitters in the brain. Also known as…
scurvy A disorder that is caused by lack of vitamin C. Symptoms include anemia; soft, bleeding gums; and bumps under the skin near muscles. Scurvy in early childhood can cause musculoskeletal problems. Treatment involves including foods that are high in vitamin C in the diet and taking vitamin C supplements if necessary.
scrotum The pouch of skin that contains the testes, epididymides, and lower portions of the spermatic cords.
scrofula Tuberculosis of the lymph nodes in the neck. Also known in the past as the King’s evil. See also tuberculosis.
scratch test for allergy See allergy skin test.
scrape An abrasion or cut that is caused by something rubbing roughly against the skin. Redness, swelling, increased pain, and pus indicate infection that requires professional care.
scoliosis, structural A fixed lateral (sideways) curve of the spine. The causes of structural scoliosis include cerebral palsy, polio, muscular dystrophy, Marfan syndrome, infections of the spine, and tumors of the spine. Structural scoliosis is different from functional scoliosis, in which the spine appears to have a lateral curve (scoliosis) but is structurally normal.
scoliosis, idiopathic Lateral (sideways) curving of the spine whose cause is unknown.
scoliosis, functional Lateral (sideways) curving in a structurally normal spine. For example, functional scoliosis can be caused by pain on one side of the back that results in splinting. Also known as nonstructural scoliosis. See also scoliosis, structural.