casoni test is an immediate hypersensitivity skin test previously used in the diagnosis of hydatid disease. Intradermal injection of 0.2ml of hydatid fluid collected from animal/human cyst which is sterilized by seitz filtration OR membrane filtration. equal volume of saline(control) injected on the other forearm and observation made for next 30 min and after 1 to 2 days. As a precaution anaphylactic tray must be kept ready before carrying out the test.(Type 1 hypersensitivity reaction) Interpretation: Sensitive patients develop large wheal measuring 5 cm or more with formation of pseudopodia like projection within 30 minutes occuring at injection site, considered positive result.(immediate hypersensitivity) . No reaction in the control arm. Disadvantage: It has low sensitivity (60-80%) and gives false positive results in cross reactive cestode infections. It is no longer used nowadays and replaced largely by the serological tests. Less reliable than imaging technique.

1. Casoni intradermal test
Ajay Subedi
Janamaitri foundation institute of health
sciences,Balaju,Kathmandu

2. Introduction
• Human Echinococcosis is a parasitic disease caused by larval stage
of tapeworms of the genus Echinococcus.(E.granulosus &
E.multilocularis)
• E.granulosus (DOG TAPEWORM) causes cystic echinococcosis
(hydatid cyst disease), which is characterized by large slow-growing
cysts, commonly in liver or lungs.
• Infective stage is the embryonated egg in feces & Diagnostic stage
is hydatid cyst in organs.
• Humans are infected through ingestion of parasite eggs in
contaminated food, water or soil, or through direct contact with
animals.(zoonotic disease)
• Remain asymptomatic for many years and symptoms may not
present until cyst or larval mass becomes large enough to produce
local mass effects.(0.3-1 cm per year).

3. (Embryonated)

6. Diagnosis

7. Casoni test
• The Casoni test is a skin test used in the
diagnosis of hydatid disease.
• Introduced by Casoni in 1911.

8. Principle Of Casoni's Skin Test
• casoni test is an immediate hypersensitivity skin test
previously used in the diagnosis of hydatid disease.
• Intradermal injection of 0.2ml of hydatid fluid collected
from animal/human cyst which is sterilized by seitz
filtration OR membrane filtration.
• equal volume of saline(control) injected on the other
forearm and observation made for next 30 min and
after 1 to 2 days.
• As a precaution anaphylactic tray must be kept ready
before carrying out the test.(Type 1 hypersensitivity
reaction)

9. Interpretation: Sensitive patients develop large
wheal measuring 5 cm or more with formation
of pseudopodia like projection within 30
minutes occuring at injection site, considered
positive result.(immediate hypersensitivity) .
No reaction in the control arm.

10. Disadvantage: It has low sensitivity (60-80%)
• and gives false positive results in cross
reactive cestode infections.
• It is no longer used nowadays and replaced
largely by the serological tests.
• Less reliable than imaging technique.

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