I. Specific diagnostics
The preparation is used for setting up skin tests (scarification, prik-test and intradermally). Specific diagnostics, as a rule, are carried out simultaneously with other pollen allergens. During one procedure, up to 15 samples with pollen allergens of various denominations are allowed to be carried out. For 2-3 days before the setting of skin tests, antihistamines should be canceled. With doubtful results of skin tests, they can be repeated two days after the local reaction to the previous samples subsided. In case of a positive result, skin tests with pollen allergens can be repeated no more than once a month.
Setting scarification skin tests, prik-tests
Scarification skin tests, prik-tests put on the inner surface of the forearm or, if necessary, on the skin of the back.
Simultaneously with the allergen, dermal samples were made with test-control fluid and with a 0.01% histamine solution prepared by diluting 0.1% histamine dihydrochloride solution (1 part) sodium chloride solution 0.9% (9 parts), positive reaction to which is not less than "+" indicates the presence of sufficient reactivity of the skin. The diluted solution of histamine is suitable for 6 hours from the moment of preparation.
The metal cap of the vials (with the allergen, test-control liquid) is rubbed with alcohol. Remove the central cap of the cap using a sterile forceps, and pierce the rubber stopper, pretreated with 70% ethyl alcohol, with a sterile needle.
The skin of the inner surface of the forearm is wiped with 70% ethyl alcohol and allowed to dry. A drop of the tested allergen is applied to the disinfected skin using a sterile syringe, a drop of test-control fluid and a drop of 0.01% histamine solution at a distance (30 ± 10) mm from each other. Allergen, typed in a syringe, can not be poured back into the vial.
When setting skarifikatsionnyh skin tests through drops of applied solutions with sterile scarifiers or injection needles, two parallel scratches with a length of 5 mm are applied.
When prik-tests are applied through droplets of applied solutions with sterile injecting needles, shortened or with the depth stop of the prick or needles for prik-test (lancets), the skin is injected to a depth of 1.0-1.5 mm. When using injection needles, the skin is pierced at an angle of 45 ° so that blood does not protrude; then the needle is removed, slightly lifting the skin.
After 15-20 minutes, sterile cotton swabs "drip" the drops of applied solutions at the site of scratches or puncture of the skin (a cotton swab should be separate for each drop of applied solutions) and take into account the skin reaction.
Injection of intradermal samples
Intradermal tests are set in cases where the scarification skin test gives a negative reaction, and a history of susceptibility to white pollen pollen is suspected, and / or if allergometric titration is necessary before the initiation of specific immunotherapy.
Intradermal tests are performed on the inner surface of the forearm.The skin is pulled downward by moving the finger downwards, the needle is inserted at an angle of 15 ° to the surface of the skin, and it must be ensured that the needle hole is completely hidden in the epidermis, the needle must be thin with a short point.
Sterile, individual for the allergen and test control fluid, marked syringes with a scale of 0.02 ml, strictly intracutaneously injected 0.02 ml of the allergen and test-control fluid, a sample with 0.01% histamine solution is put by the method of scarification. Allergen, typed in a syringe, can not be poured back into the vial.
Evaluation of diagnostic skin tests
The local skin reaction during the formulation of scarifying skin tests, prik-tests are taken into account after 15-20 minutes, intradermal tests - after 20 minutes in the absence of reaction to the test control fluid and in the presence of a positive sample for histamine (not less than "+") (Table. 1).
Table 1. Scheme of accounting for scarification skin tests, prik-tests
Evaluation of reaction | Power manifestations reactions * | The size and nature of the reaction |
Negative | _ | Absence of blister (papules), hyperemia with dimensions both in control with test-control fluid |
Doubtful | ± | Absence of blister (papules), hyperemia with sizes exceeding those in control with test-control fluid |
Positive | + | Wheal (papule) 2-3 mm, only noticeable when the skin stretching is congestion (for prick tests); Blister (papule) 3-5 mm, visible only when stretching the skin, hyperemia (for prik-tests) |
Positive | ++ | Blister (papule) 4-5 mm, hyperemia (for scarification tests); Blister (papule) 5-10 mm, hyperemia (for prik-tests) |
Positive | +++ | Blister (papule) 6-10 mm, hyperemia or blister (papule) 6-10 mm with pseudopodia, hyperemia (for scarification tests); Blister (papule) 10-15 mm, hyperemia (for prik-tests) |
Positive | ++++ | Blister (papule) more than 10 mm, hyperemia or blister (papule) more than 10 mm with pseudopodia, hyperemia (for scarification tests); Blister (papule) more than 15 mm with pseudopodia, hyperemia (for prik-tests) |
Scheme of recording intradermal samples
Evaluation of reaction | Power manifestations reactions * | The size and nature of the reaction |
Negative | - | Dimensions are the same as in the control |
Doubtful | ± | At the test site, the blister dissolves more slowly than in the control |
Positive | + | Blister (papule) 4-7 mm in diameter, surrounded by hyperemia |
Positive | ++ | Blister (papule) 8-14 mm in diameter, surrounded by hyperemia |
Positive | +++ | Blister (papule) 15-20 mm in diameter with pseudopodia, surrounded by hyperemia |
Positive | ++++ | Blister (papule) more than 20 mm in diameter with pseudopodia and (or) erythema around (additional blisters around the periphery of pink or bright red) |
EtcimchaMr.th:
* Degree of severity of reaction:
- Negative;
± Doubtful;
+ Weakly positive;
++ Positive;
+++ Sharply positive;
++++ Very sharply positive.
II. Specific immunotherapy
Specific immunotherapy is carried out in those cases when it is impossible to exclude the contact of a sensitized patient with an allergen.
Immunotherapy starts with a dose 10 times lower than the one that caused a minimal positive reaction with intradermal administration.
Allergen for specific immunotherapy is administered subcutaneously.
For the correct preparation and use of dilutions of the allergen with compliance with asepsis, the responsibility is borne by the allergist doctor.
Dilutions of the drug, the volume administered (dose) and the recommended scheme of application are given in Table 2.
Table 2. An example scheme of specific immunotherapy in pollinosis
Breeding allergen | Dose (ml) | Notes |
1 | 2 | 3 |
10-5 1:100000 0,1 PNU/ ml | 0,1 0,2 0,4 0,8 | Specific immunotherapy is initiated after diagnosis of atopic disease no later than 3-4 months before the beginning of flowering and completed no later than 1.5 months before the flowering of plants. Injections are made strictly subcutaneously in the region of the lower third of the shoulder. The first injection (when diluting the allergen 10-5, 10-4, 10-3) are doing daily or every other day, subsequent injections (dilutions of 10-2, 10-1) - with an interval of 7-10 days. The dose of the allergen is 0.9-1.0 ml in dilution 10-1 repeat with an interval of 5-7 days before the beginning of flowering of plants. The period of use of the allergen after its dilution is 1 month. After each injection of the patient's allergen, the patient is observed in the office for at least 60 minutes. The doctor notes the skin reaction at the site of the allergen injection and the general condition of the patient. Contraindication to increase the dose is a local reaction in the form of an infiltrate larger than 25 mm, arising during the day at the injection site, the general reaction of the body, the aggravation of the underlying disease. In these cases, the dose is reduced, the intervals between injections are extended until good tolerability is established. |
10-4 1:10000 1,0 PNU/ ml | 0,1 0,2 0,4 0,8 |
10-3 1:1000 10 PNU/ ml | 0,1 0,2 0,4 0,8 |
10-2 1:100 100 PNU / ml | 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0 |
10-1 1:10 1000 PNU/ ml | 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0 |