Schick test
Schick test,
diagnostic test designed to evaluate susceptibility to diphtheriadiphtheria, acute contagious disease caused by Corynebacterium diphtheriae (Klebs-Loffler bacillus) bacteria that have been infected by a bacteriophage. It begins as a soreness of the throat with fever.
..... Click the link for more information. . A small amount of diphtheria toxintoxin,
poison produced by living organisms. Toxins are classified as either exotoxins or endotoxins. Exotoxins are a diverse group of soluble proteins released into the surrounding tissue by living bacterial cells. Exotoxins have specific reaction sites in the host; e.g.
..... Click the link for more information. is injected into the skin; the injection will produce an area of redness and swelling in individuals with low levels of antibodyantibody,
protein produced by the immune system (see immunity) in response to the presence in the body of antigens: foreign proteins or polysaccharides such as bacteria, bacterial toxins, viruses, or other cells or proteins.
..... Click the link for more information. (i.e., little immunityimmunity,
ability of an organism to resist disease by identifying and destroying foreign substances or organisms. Although all animals have some immune capabilities, little is known about nonmammalian immunity.
..... Click the link for more information. ) against the toxin. If the individual is immune to diphtheria, the antibody in the system will neutralize the toxin and no skin reaction will occur.
Schick Test
a skin test used to determine human susceptibility to diphtheria; one of the allergy-based diagnostic tests, proposed in 1913 by the Austrian pediatrician B. Schick. Dilute active diphtheria toxin is injected into the skin. Local inflammation (reddening, edema) develops three to four days later, and an individual’s reaction is evaluated from the severity of the inflammation. The Schick test is used to determine which individuals, primarily children, should be vaccinated against diphtheria.