Norm of Schick Test for Diphtheria
Usage of Schick Test for Diphtheria
Measurement of immunity to diphtheria. To eliminate the carrier state of strains during epidemics.
Description of Schick Test for Diphtheria
The Schick test is an intracutaneous skin test to determine the immunity strain for diphtheria by detecting the presence of antitoxins in the blood to this respiratory disease. One performs the test by injecting 1/50 of the minimum lethal dose of diphtheria toxin and then observing the site for a reaction, which would indicate lack of diphtheria immunity. A negative response indicates the presence of diphtheria antitoxin in the client's bloodstream. Immunity to diphtheria wanes over time; therefore a childhood vaccination does not guarantee immunity in adulthood.
Professional Considerations of Schick Test for Diphtheria
Consent form NOT required.
- Obtain two intradermal needles with syringes, and two alcohol pads.
- Cleanse areas on the forearm with alcohol pads and allow the areas to dry.
- Inject intracutaneously 0.1 mL of purified diphtheria toxin into one forearm and 0.1 mL of inactivated diphtheria toxoid into the other forearm.
- Observe the sites for reaction 24–48 hours later (no longer than 120 hours). Absence of erythema, induration, and necrosis at the site is indicative of immunity to diphtheria.
- Leave the injection sites open to air.
- For positive responses, inject 1/13 U of diphtheria antitoxin to neutralize the toxin.
Client and Family Teaching
- This test will indicate whether you are immune to diphtheria.
- The recommended schedule for active immunization of children is 2 months, 4 months, 6 months, 18 months, and 4–6 years of age.
Factors That Affect Results
- Expired toxin will cause false-negative results.
- If a client has been actively immunized but the Schick test is positive, the client is unable to produce antibodies.