Standardized mite extract is indicated for use in the diagnosis of patients with a history of allergy to
mites or house dust and for the treatment of patients with a history of mite allergy who have established
sensitivity to mites by diagnostic skin testing.
The use of mite extract for the above purposes should be made only by physicians with special
familiarity and knowledge of allergy as described in a standard allergy textbook10 .
DOSAGE AND ADMINISTRATION
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to
administration, whenever solution and container permit. The product should be discarded if
discoloration or particles are observed.
The skin test concentration of 10,000 AU/mL in dropper vials is used for scratch or prick-puncture
testing. Puncture tests performed with D. farinae extract on 5 persons sensitive to mite showed a mean
diameter wheal of 8.8 mm ± 1.8 mm and mean diameter erythema of 39.2 mm ± 5.3 mm.
Puncture tests with D. pteronyssinus extract on 10 persons sensitive to mite showed a mean diameter
wheal of 7.8 mm ± 4.1 mm and mean erythema of 33.7 mm ± 12.0 mm.
Extract for intradermal testing should be prepared by diluting the 10,000 AU/mL stock concentrate in
bulk vials with sterile saline with or without human serum albumin.
Intradermal skin tests (0.05 mL) in persons highly sensitive to mite showed the following results:
AU/mL to elicit 50 mm sum of diameter
Intradermal Extract Should Be Used As Follows
Intradermal tests should only be performed after a scratch or prick-puncture test has been administered
with a negative result. Patients who do not react to a valid scratch or prick-puncture test should be
tested intradermally with 0.02 to 0.05 mL of a 10 AU/mL (1:1,000 v/v of the 10,000 AU/mL
concentrate). If this test is negative, a second intradermal test may be performed using a 100 AU/mL
(1:100 v/v dilution of 10,000 AU/mL concentrate). Skin tests are graded in terms of the wheal and
erythema response noted at 1 5 to 20 minutes. Wheal and erythema size may be recorded by actual
measurement of the extent of both responses.
The dosage of mite extract administered by subcutaneous injection is highly individualized and varies
according to the degree of sensitivity of the patient, his clinical response and tolerance to the extract
administered during the early phases of an injection regimen. In patients who appear to be highly
sensitive by history and skin test, the initial dose of the extract should be 0.05 mL of a 0.1 AU/mL
dilution or as established by skin test titration. The amount of allergenic extract is increased at each
injection by not more than 50% - 100% of the previous amount, and the next increment is governed by
the response to the last injection. Large local reactions which persist for longer than 24 hours are
generally considered an indication for repeating the previous dose or reducing the dose. Any evidence
of systemic reaction is an indication for a significant reduction (at least 50%) in the subsequent dose.
The upper limits of dosage have not been established; however, doses larger than 0.2 mL of the
concentrate may be painful due to the glycerin content of the extract.
The optimal interval between doses of mite extract has not been definitely established. However, as is
customarily practiced, injections are given one or two times per week until the maintenance dose of
extract is reached. At this time, the injection interval may be increased to 2 weeks, then to 3 weeks and
finally to 4 weeks. If the patient does not return for 6 to 8 weeks after the last injection, the dose should
be reduced to 25% of the last dose. If longer than 8 weeks, a dose reduction of one, too or three
dilutions may be made depending on a consideration of the components and the patient's sensitivity The
dosage and the interval between injections may need to be modified according to the clinical response
of the patient. When switching patients to fresh extract, the initial dose should be reduced to one-quarter
(25%) of the previous dose.
The usual duration of treatment has not been established. A period of three to five years of injection
therapy constitutes an average course of treatment.
Children and older age patients appear to tolerate injections of allergenic extract well, and no special
recommendations need to be made for these groups.
To prepare dilutions for intradermal skin tests and therapeutic use, the stock concentrate may be diluted
as shown in Table 1. Vial #1 is made by adding 1.0 mL of the concentrate to 9.0 mL of sterile diluent. Vial #2 is made by adding 1.0 mL of Vial #1 to 9.0 mL of sterile diluent. This process is repeated until
the desired concentration is achieved. In each case, the subsequent vial is made by adding 1.0 mL of the
previous dilution to 9.0 mL of sterile diluent. The number of allergy units per mL in each dilution is
shown in table below.
Volume per volume dilutions of 5,000 AU/mL and 10,000
AU/mL concentrates to provide a ten-fold dilution s eries .
||w/v Dilution of
Extract of D. farinae and D. pteronyssinus containing 5,000 and 10,000 Allergy Units per mL is supplied
in 50% glycerol v/v in 10 mL, 30 mL and 50 mL vials. Extract containing 10,000 Allergy Units per mL
is supplied in 50% glycerol v/v in dropper vials for scratch or prick-puncture testing. An equal v/v
mixture of the two mites is offered in 10, 30 and 50 mL vial sizes at a concentration of 2,500 AU/mL or
5,000 AU/mL for each mite. see DESCRIPTION above for the complete list of the active and inactive
ingredients of this product.
Extract of D. farinae and D. pteronyssinus may be diluted in sterile buffered saline containing 0.4%
phenol or in sterile buffered saline containing human serum albumin and 0.4% phenol.
10. Middleton, E. Jr., C.E. Reed, F.E. Ellis, N.F. Adkinson Jr., J.W. Yunginger, W.W. Busse, Allergy
Principles and Practice, 5th Ed., Vol II, 394-404, 1050., Mosby, St. Louis, 1998.
Manufactured By: Allermed Laboratories , Inc. Revised: January 2009