ALLERGENIC EXTRACTS STANDARDIZED MITE- dermatophagoides farinae concentrate
ALLERGENIC EXTRACTS STANDARDIZED MITE- dermatophagoides pteronyssinus concentrate
ALLERGENIC EXTRACTS STANDARDIZED MITE- dermatophagoides farinae and dermatophagoides pteronyssinus concentrate
Greer Labortories, Inc.
- Do not inject intravenously. (2.2)
- Allergenic extracts may potentially elicit a severe life-threatening systemic reaction, rarely resulting in death. (5.1)
- This allergenic product is intended for use only by physicians who are experienced in the administration of allergenic extracts and the emergency care of anaphylaxis, or for use under the guidance of an allergy specialist. (5.1)
- The initial dose must be based on skin test. (2.1)
- Observe patients in the office for at least 30 minutes following treatment. Emergency measures and personnel trained in their use must be available immediately in the event of life threatening reaction. (5.1)
- Immunotherapy may not be suitable for patients with medical conditions that reduce their ability to survive a systemic reaction, including significant cardiovascular and/or pulmonary diseases. Patients who are receiving beta blockers may be unresponsive to the usual doses of epinephrine used to treat systemic reactions, including anaphylaxis. (5.2)
Greer Standardized Mite (Dermatophagoides farinae and/or Dermatophagoides pteronyssinus) Extracts are allergenic extracts indicated for
- skin test diagnosis of mite allergy
- treatment of patients with mite-induced allergic asthma, rhinitis and conjunctivitis.
For immunotherapy, patients must show hypersensitivity to Dermatophagoides farinae (D. farinae) or Dermatophagoides pteronyssinus (D. pteronyssinus) based on their clinical history, allergen exposure history, and skin test reactivity.
Do not inject intravenously.
Greer Standardized Mite extracts are diluted with sterile diluent for allergenic extracts when used for intradermal testing or subcutaneous immunotherapy. Dosages vary by mode of administration, and by individual response and tolerance. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Greer Standardized Mite Extracts should be a light brown solution that is free of particulate matter. If particulate matter is observed then the solution should be discarded.
For diagnosis of a patient with a suspected allergy to either species of dust mite (D. farinae or D. pteronyssinus), diagnostic skin testing should include the standardized mite mixture or the single-species mite extracts.
- If a skin test with the standardized mite mixture elicits a positive reaction, then the single-species mite extracts can be used to determine the degree of sensitivity to each, and to guide in the selection of extracts and their concentration for immunotherapy, if indicated.
- A positive skin test reaction to any allergen must be interpreted in light of the patient’s history of symptoms, the time of year, and known exposure to environmental allergens.
2.1.1 Percutaneous Skin Testing
For percutaneous (scratch, prick, or puncture) testing, use 10,000 Allergy Units/mL Greer Standardized Mite Extract stock concentrate in dropper vials. If patient is suspected of having exquisite sensitivity, such as anaphylaxis, to certain foods and drugs, initiate percutaneous testing with several serial 10-fold dilutions of the usual test concentration.
- For scratch tests, scarify the skin, and then apply one drop of the extract to the scratch.
- For prick tests, place one drop of extract on the skin and pierce through the drop into the skin with a slight lifting motion.
- For puncture tests, place one drop of extract on the skin and pierce through the drop perpendicular to the skin.
When using percutaneous test devices, follow the directions provided with the test devices.
Include a positive control to detect false negative responses to skin testing, which may occur if serum levels of antihistamines remain from prior medication administration [see Drug Interactions (7.2) ]. A glycerinated histamine phosphate diluted to 10mg/mL (6mg/mLhistamine base) may be used as the positive control.
Include a negative control to detect false positive responses, which can occur when the patient has a non-specific reaction to the diluent. A 50% glycerosaline solution may be used as the negative control.
Read skin tests 15-20 minutes after exposure. Record the induration (wheal) and erythema (flare) response by noting the longest diameter of each, or by the sum of the longest erythema diameter and the mid-point orthogonal diameters of erythema (ΣE).
Percutaneous testing devices often have their own grading systems, as these devices may cause different degrees of trauma to the skin and deliver different volumes of allergenic extract. Follow grading instructions for the device used.
2.1.2 Intradermal Skin Testing
Intradermal tests are commonly used when the reaction to percutaneous testing is negative or equivocal but the patient has a strong clinical history of symptoms triggered by exposure to a specific allergen. Because immediate systemic reactions are more common with intradermal testing, prescreening with percutaneous testing is a practical safety measure.1
Dilute the stock concentrate with sterile diluent. Use saline with human serum albumin (HSA), buffered saline, or saline. If prescreening is not done, or if patients are expected to be high risk, precautions should be observed since some patients have experienced anaphylaxis and death.
- Patients who do not react to percutaneous skin testing should be tested intradermally at a starting dose of 0.02 to 0.05 mL of a 50 Allergy Units/mL extract dilution.
- Patients suspected of being highly allergic should first receive a test dose of 0.02 to 0.05 mL of a 0.05 Allergy Units/mL extract dilution.
- If the initial dose test is negative, subsequent intradermal tests using increasingly stronger doses may be performed up to the maximum recommended strength of 200 Allergy Units/mL.
- If percutaneous skin testing was not performed, include a positive control to detect false negative responses to skin testing, which may occur if serum levels of antihistamines remain from prior medication administration [see Drug Interactions (7.2) ]. A glycerinated histamine phosphate diluted to 0.5 mg/mL (0.18 mg/mL histamine base) or aqueous histamine phosphate 0.275 mg/mL (0.1 mg/mL histamine base) may be used as the positive control.
- If percutaneous skin testing was not performed, include a negative control to detect false positive responses, which can occur when the patient has a non-specific reaction to the diluent. A 1% glycerin in 0.9% saline solution may be used as the negative control.
- Measure the wheal-and-flare response after 15-20 minutes, which may be graded using variou methods as described in the instructions for the device used.
The mean dose of Greer dust mite allergen required to elicit a positive intradermal test result (ΣE ≥ 50 mm) in a total of 83 mite puncture test positive (ΣE ≥ 20 mm) persons is shown in Table 1.
|Allergen||Number of Persons||Dose to Elicit 50 mm Sum of Diameter Erythema Reaction|
|Mean (AU */mL)||Range (AU/mL)|
|D. farinae||46||0.00856||0.00004 – 1.75935|
|D. pteronyssinus||37||0.00570||0.00002 –1.36341†|
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