Schick Test : Diagnosis-Benefits

 What Is a Schick Test?

Schick Test, approach for determining susceptibility to diphtheria; it laid the premise for inoculation in opposition to the disorder. A minute quantity of diphtheria toxin is injected into the pores and skin of the forearm. Redness on the injection after 3 days shows a positive reaction (absence of circulating antibody) or a false effective reaction (allergic reaction to the toxin). A fantastic reaction can be outstanding with the aid of use of a control injection of the equal amount of heated toxin (toxoid) into the other forearm. The Schick took a look and was brought in 1913 with the aid of Bela Schick (1877–1967), an Austrian pediatrician.

The Schick test detects immunity to diphtheria, both received through previous infection or vaccination.

A small amount of diphtheria toxin in 0.2ml is injected intradermally into the left forearm. An equivalent quantity of warmth-inactivated toxin in 0.2ml is injected into the right forearm. The test is studied at 1-four days, the maximal reaction going on on day four.

Those who're Schick negative will haven't any pores and skin reaction. This is because of enough antitoxin being present in the movement to neutralize the toxin. A sick man or woman is immune and need not be immunized or strengthened. At worst, if they come to be inflamed, they will most effectively suffer a mild assault.

A Schick advantageous check is an erythematous response growing on the website online of the toxin injection after a day or  and persisting for seven or more days before fading. Schick superb individuals are liable to diphtheria.

Occasionally, a mild response may occur in the right arm handiest. This is a non-precise response to bacterial protein. It disappears by way of day four. The person is Schick terrible.


The Schick test is a diagnostic test used to determine whether an individual is immune or susceptible to diphtheria, a bacterial infection caused by Corynebacterium diphtheriae. The test is named after its inventor, Bela Schick, a Hungarian-born American pediatrician. Here's how the Schick test works and its benefits:

How the Schick Test Works:

  • Diphtheria Toxin: The test relies on the administration of a small amount of diphtheria toxin (or toxoid) under the skin. Diphtheria toxin is a protein produced by the bacterium Corynebacterium diphtheriae, and it is responsible for the symptoms of diphtheria.

  • Immune Response: If an individual has previously been exposed to diphtheria or has received a diphtheria vaccine, their immune system would have produced antibodies against the toxin. These antibodies provide protection against diphtheria.

  • Skin Reaction: When the diphtheria toxin is injected under the skin (usually in the forearm), two reactions can occur:

    • Positive Reaction: If the person is not immune to diphtheria, there will be an inflammatory response at the injection site, indicating susceptibility to the disease.

    • Negative Reaction: If the person is immune to diphtheria, there will be little to no reaction at the injection site, suggesting protection against the disease.

Benefits of the Schick Test:

  • Diphtheria Susceptibility Assessment: The primary benefit of the Schick test is its ability to determine whether an individual is susceptible to diphtheria. This information is crucial for vaccination strategies and public health planning.

  • Vaccination Guidance: The test can help healthcare professionals identify individuals who need diphtheria vaccination. If a person is found to be susceptible (positive reaction), they may be recommended to receive the diphtheria vaccine to protect them from the disease.

  • Avoiding Unnecessary Vaccination: On the other hand, if the test shows that a person is already immune (negative reaction), there is no need for additional diphtheria vaccination, saving resources and potentially reducing the risk of adverse vaccine reactions.

  • Epidemiological Surveillance: The Schick test can also be used in epidemiological studies to assess the prevalence of diphtheria susceptibility in a population. This information helps public health authorities plan vaccination campaigns and monitor disease trends.

It's worth noting that while the Schick test has been historically used for diphtheria susceptibility assessment, many countries have transitioned to routine diphtheria vaccination as part of childhood immunization programs. In such cases, the Schick test may be less commonly employed because widespread vaccination has greatly reduced the incidence of diphtheria in vaccinated populations. Public health practices and recommendations may vary by region and time, so it's important to consult with healthcare professionals for the most up-to-date guidance on diphtheria vaccination and testing.

Take a check test

The test is easy. A small quantity (zero.1 ml) of diluted (1/50 MLD) diphtheria toxin is injected intradermally into one arm of the character and a warmness inactivated toxin on the opposite as a manipulate. If someone no longer has sufficient antibodies to fight it off, the skin across the injection turns purple and swollen, indicating a fine result. This swelling disappears after a few days. If the individual has an immunity, then very little swelling and redness will arise, indicating a poor end result.

Results may be interpreted as:

  • Positive: when the test results in a wheal of five–10 mm diameter, attaining its peak in 4–7 days. The control arm shows no response. This shows that the situation lacks antibodies against the toxin and consequently is prone to the disorder.

  • Pseudo-effective: when there's only a crimson-coloured infection (erythema) and it disappears within four days. This takes place on both the fingers because the problem is immune but hypersensitive to the toxin.

  • Negative reaction: Indicates that the man or woman is immune.

  • Combined response: Initial photo is like that of the pseudo-response but the erythema fades off after 4 days simplest inside the control arm. It progresses at the check arm to a standard wonderful. The problem is interpreted to be both susceptible and hypersensitive.

The check was created while immunizing marketers were scarce and now not very secure; however, as newer and safer toxoids have become available, susceptibility exams have been now not required.

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