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.
Skin tests are placed 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 a test-control fluid and with a 0.01% histamine solution, which was prepared by diluting 0.1% histamine dihydrochloride solution (1 part) sodium chloride solution 0.9% (9 parts).A diluted solution of histamine is suitable for 6 hours from the time of preparation.
A metal cap of vials (with allergens or 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 scarifying skin samples are put through the applied drops with a sterile scarification needle, 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 the anamnesis is suspected of increased sensitivity to ash-leaf maple pollen, 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 each allergen and test-control fluid with marked syringes with a scale of 0.02 ml division, 0.02 ml of allergen and test-control liquid are strictly administered intradermally, a test 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.
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).
Evaluation of reaction | Degree of expression of the reaction * | 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 | + | Blister (papule) 2-3 mm, visible only when stretching the skin, hyperemia (for scarification 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 | Degree of expression of the reaction * | 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) |
Note:
* 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.
The dilutions of the drug, the volume administered (dose) and the recommended scheme of application are given in Table. 2.
Breeding | Dose (ml) | Notes |
allergen | | |
1 | 2 | 3 |
10-5 1:100000 0.1 PNU / ml | 0,1 0,2 0,4 0,8 | Specific immunotherapy begins after diagnosis of atopic disease no later than 3-4 months before the beginning of flowering and is completed no later than 1.5 months before the beginning of flowering of plants. Injections are made strictly subcutaneously in the outer surface of the lower third of the shoulder. The first injection (when diluting the allergen 10-5, 10-4, 10-3) are done 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 flowering of trees and grasses. The period of use of the allergen after its dilution is 1 month. After each injection of the allergen, the patient is observed in the office for 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, the general reaction of the body, exacerbation of the underlying disease. In these cases, the dose is reduced, the intervals between injections are extended until good tolerability is established. |
10-4 1:100000 1.0 PNU / ml | 0,1 0,2 0,4 0,8 |
10-3 1:100000 10 PNU / ml | 0,1 0,2 0,4 0,8 |
10-2 1:100000 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 1:100000 1000 PNU / ml | 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0 |
Precautions for use.
In particularly sensitive patients, a systemic allergic reaction and anaphylactic shock can occur. In this regard, in the office, where specific diagnostics and specific immunotherapy of patients are carried out, there should be pharmacological preparations and tools for providing urgent
assistance.
Assisting with general reactions and anaphylactic shock.
After the introduction of the allergen, symptoms of clinical manifestations of hypersensitivity to the allergen may develop. With parenteral administration of an allergen, it is possible to develop an immediate-type reaction, incl. anaphylaxis, which manifests itself in the form of urticaria and vascular edema, laryngeal edema, shortness of breath and suffocation.These symptoms often occur after feeling generalized itching, burning sensation, skin flushing, and a sense of fear of death.
As a result of anaphylactic shock, non-occuring bronchospasm, asphyxia due to edema of the upper respiratory tract, and collapse can develop.
In this case, urgent medical measures are required.
Pre-hospital care for anaphylactic shock.
1. Immediately stop the introduction of the allergen that caused the reaction, put the patient on the couch (head below the legs), turn the head to the side, push the lower jaw, remove the existing dentures.
2. Apply the tourniquet in place above the allergen injection, if possible.
3. Add 0.3-0.5 ml of 0.1% adrenaline solution intramuscularly (IM) or intravenously (IV) to the limb-free limb (children 0.01 mg / kg, maximum to 0, 3 mg). If necessary, the administration of these doses is repeated at intervals of 10-20 minutes. The total dose of epinephrine should not exceed 1 ml of 0.1% solution. The multiplicity and dose of adrenaline administered depends on the severity of the shock and blood pressure. Repeated administration of small doses of epinephrine is more effective than single administration of a large dose.
4.Finish the injection site with 0.3-0.5 ml of adrenaline solution (1 ml of 0.1% solution of epinephrine diluted in 3-5 ml of sodium chloride solution 0.9%).
5. Apply an ice pack to the injection site.
6. Provide access to fresh air or give oxygen. If the rhythm of breathing is disturbed or if it is difficult, perform artificial ventilation (IVL).
7. Urgent call the doctor, simultaneously called the resuscitation team.
Before the arrival of the resuscitation team, it is necessary to provide medical care and carry out constant monitoring of hemodynamic parameters and the state of the function of external respiration (FVD).
Hospital care for anaphylactic shock.
1. In extremely severe condition of the patient and with severe hemodynamic disorders, 5 ml of 0.01% solution of epinephrine are injected slowly into IV, when the effect is achieved, the administration is terminated. Children 0.1 ml / kg 0.01% solution injected slowly for several minutes.
2. If blood pressure (BP) does not stabilize, urgently begin intravenous drip injection of norepinephrine (phenylephrine, dopamine) 0.2% 1.0-2.0 ml per 500 ml of 5% glucose solution for infusion or sodium chloride solution 0.9 %.
3. Intravenously inject glucocorticosteroids: prednisolone 60-180 mg (children 5 mg / kg) or dexamethasone - 8-20 mg (children 0,3-0,6 mg / kg), or hydrocortisone - 200-400 mg (children 4-8 mg / kg). As of the introduction of hormones, repeat and continue at least 4-6 days to prevent allergic reactions by immunocomplex or delayed type.
4. Only with the stabilization of blood pressure intramuscularly to enter 2.0 ml of a 2% solution of chloropyramine (children 6-12 months - 0.25 ml, 1-6 years - 0.5 ml, 7-18 years - 0.5-1, 0 ml) or 0.1% clemastine (children 0,025 mg / kg / day for two injections).
5. Symptomatic therapy according to indications. At bronhospazme 10.0 ml of a 2.4% solution of aminophylline on sodium chloride solution 0.9% (2-3 mg / kg for children) is injected intravenously. If necessary, enter cardiac glycosides, respiratory analeptics.
6. If necessary, suck from the respiratory tract accumulated secret and vomit, begin oxygen therapy.
7. In case of acute edema of the larynx, intubation or tracheotomy is indicated.
All patients with anaphylactic shock are subject to compulsory admission for a period of at least 10 days in order to continue monitoring and treatment, In 2-5% of patients who have had anaphylactic shock, late allergic reactions are observed.
Doses of drugs administered and the tactics of the doctor are determined by the clinical picture, but in all cases it is necessary, first of all, the introduction of adrenaline, glucocorticosteroid preparations.The administration of preparations of phenothiazine series and calcium preparations is contraindicated.