Diseases & National Health Programme
Positive Schick’s test indicates that the person is:
|A|| Immune to diphtheria |
|B|| Hypersensitive to diphtheria|
|C|| Susceptible to diphtheria|
|D||Susceptible & hypersensitive to diphtheria|
a. Injecting I/D into skin of forearm 0.2 ml of Schick test toxin, while into opposite arm, is injected as a control- same amt. of antitoxin, inactivated (better control – fluid toxoid vaccine preparation)
b. Negative Reaction- no reaction of any kind on either arm- immune to diphtheria->0.03 units of antitoxin/ml
c. Positive reaction- in test arm-circumscribed red flush- 10-50 mm dia- generally appears within 24-36 hrs – max. 4-7 day, slowly fades, desquamates; control arm shows no reaction- person is susceptible
d. Pseudo positive reaction- a red flush equally on both arms, but less circumscribed than the true positive reaction, reaction fades very quickly and disappears by 4th day – allergic type of reaction- Schick test negative
e. Combined reaction- control arm shows pseudo negative reaction , test arm is true positive. The person is susceptible to diptheria.
f. A person who is proved to be susceptible but allergic- vaccination with caution.
i. (-) Not Susceptible & No Hypersensitivity (HS)
ii. (+) No HS. but susceptible to diphtheria.
iii. Psuedo (+) HS. Present, Not susceptible
iv. Combined HS Present, Susceptible Diphtheria.