The document summarizes four medical skin tests: 1) The Bachman test detects the parasite Trichinella through a wheal-and-flare skin reaction. 2) The Schick test detects immunity to diphtheria by comparing reactions to live and killed diphtheria toxin. 3) The Dick test detects susceptibility to scarlet fever by comparing reactions to live and killed Strep. pyogenes toxin. 4) The Casoni test detects the parasite Echinococcus granulosus, which causes hydatid cysts, through a wheal response to injected hydatid fluid.

1. Bachman Test, Schick Test,
Dick Test & Casoni Test
Presented by:
Jeff Choa Shi
Melchemer Macalood
Kyla Morales
3-BS Biology | May 13, 2022

2. Bachman Test
1. Who discovered the test?
•In 1928 Dr. Bachman publish his papers which seemed to offer great possibilities as aids in the diagnosis
of trichinosis by precipitin and intradermal test.
•Dr. Bachman, in 1928, showed that specific precipitin and skin tests could be obtained in experimental
trichinella infections in laboratory animals. In 1932 his work was confirmed by Augustine and Theiler,
who first used the skin test as an aid to the diagnosis of trichinosis in human subjects.

3. Bachman Test
2. What are the purpose of Bachman test?
The purpose of the bachman test is to indicates the infection of trichinosis through the wheal-and-flare
reaction or a delayed response.

4. Bachman Test
3. Principle of the test.
Trichinella larvae extract is suspended in saline
and injected intradermally in a skin test for
trichinosis. Infection is indicated by a
wheal-and-flare reaction or a delayed response.
Trichinosis is a disease that people can get by
eating raw or undercooked meat from animals
infected with the microscopic parasite
Trichinella.

5. Backman Test
4. Procedure of the test.
The skin test reaction should be read
between 48 and 72 hours after
administration by a health care worker
trained to read results. A patient who does
not return within 72 hours will need to be
rescheduled for another skin test. The
reaction should be measured in millimeters
of the induration
Negative reaction: 0-5 mm

6. Schick Test
1. Who discovered the test?
The Schick test was developed by Béla Schick in 1913 who
is a Hungarian born American pediatrician.
2. What are the purpose of the test?
The purpose of the test is to assess if a person is
susceptible to diphtheria. (Bacterial infection caused by
Corynebacterium diphtheriae that makes toxins to humans leading
to difficulty breathing, heart failure, paralysis and possibly
death)

7. Schick Test
3. Principle of the test
The test detects immunity to diphtheria acquired through vaccination or previous exposure,
where a small non lethal dose of the toxin, and heat deactivated dose is injected intradermally into
each forearm to check for reactions that can indicate immunity.
4. Procedure of the test
I.0.2 ml of standard toxin is injected intradermally in the left forearm.
II.0.2 ml of heat inactivated toxin is injected into right forearm.
III.Readings are taken after a 1-4 days peaking usually at day 4.
IV.No reaction: negative
5-10mm diameter at peak means positive

8. Dick Test
1. Who discovered the test?
It was developed by American physicians George
Frederick Dick (July 21, 1881 – October 10, 1967) and Gladys
Rowena Henry Dick (December 18, 1881 – August 21, 1963) in
1924
2. What are the purpose of the test?
This test is performed in determining the susceptibility of
individuals to scarlet fever which is a type of acute pharyngitis
with an erythematous rash that is caused by Strep. pyogenes
strains that produce erythrogenic toxin.
Erythema as the dominant symptom of scarlet fever.

9. Dick Test
3. Principle of the test
Erythrogenic toxin (Scarlatinal/Dick toxin) is injected
intradermally which causes an erythematous reaction in
susceptible individuals.
4. Procedure of the test
A. 0.2 ml of standard toxin of Strep.pyogenes is injected
intradermally in one forearm.
B. 0.2 ml of heat inactivated toxin is injected into the other
forearm.
C. Readings are taken after a day (24 hours).
D. An erythema diameter of 1 cm indicates a positive result.
Typical skin reaction in a positive Dick Test.

10. Casoni Test
1. Who discovered the test?
It was introduced in 1981 by Tomaso Casoni (August 28,
1880 - September 6, 1933), an Italian physician, when hydatid
disease was endemic in Europe, Middle East and Africa.
2. What are the purpose of the test?
This immediate hypersensitivity skin test is used to
detect hydatid disease (cystic echinococcosis) caused by
Echinococcus granulosus infection.
Hydatid cyst of liver.

11. Casoni Test
3. Principle of the test
The hydatid fluid (antigen) used in this test is collected
from a cyst of an animal or human and is sterilized. The sterilized
fresh hydatid fluid is intradermally injected on one arm and equal
volume of saline on the other arm.
4. Procedure of the test
A. 0.20-0.25 ml of sterilized fresh hydatid fluid is introduced
into the forearm of an individual intradermally
B. Equal volume saline is administered on the other forearm
(Control)
C. Observations are made after 30 minutes and another after
24-74 hours.
D. A wheal response at the injection site usually within 20-30
minutes indicates a positive result
Typical skin reaction in a positive Casoni Test.

12. Thank you!
Backman Test, Schick Test,
Dick Test & Casoni Test
Presented by:
Jeff Choa Shi
Melchemer Macalood
Kyla Morales
3-BS Biology | May 13, 2022