D. FARINAE 10 000 DU/ML ODC
Active substance(s): DERMATOPHAGOIDES FARINAE
NAME OF THE MEDICINAL PRODUCT
D. farinae 10,000 DU/ml ODC
Solution for skin prick test
QUALITATIVE AND QUANTITATIVE COMPOSITION
D. farinae 10,000 DU/ml ODC in 2 ml
For the full list of excipients see Section 6.1.
Solution for skin prick test
A clear solution
This medicinal product is indicated for the diagnosis of allergic (IgE –
mediated) diseases (type 1 in the classification of Coombs and Gell).
Posology and method of administration
Taking of a careful case history is a vital part of the investigation of a patient
with allergy symptoms since it will usually identify those allergens most likely
to be clinically significant. Skin testing will help to confirm the significance of
the likely causative allergens, and establish their relative importance.
Prick testing in children is possible after the first year of life depending on the
child constitution, but in general should not be performed before the age of 4.
Method of administration
The tests are usually carried out on the volar surface of the forearm: In
conditions of extreme outdoor temperatures allow acclimatisation to room
temperature: If test area has been cleaned with water, alcohol etc, wait at least
two minutes to allow skin circulation to return to normal.
Clean the skin with soap and water if necessary – but do not sterilise with
organic solvents or strong antiseptics.
A ballpoint pen may be used to mark the skin (with suitable symbols) adjacent
to planned test sites to identify the allergen and control solutions used.
The colours of the individual skin testing solutions vary depending on the
characteristics of the raw material involved, e.g. pollens tend to be yellowish
whilst dusts and moulds in particular, are shades of brown.
Since each vial is used more than once, aseptic precautions must be sufficient
to avoid the risk of microbial contamination.
Place one drop of each of the required test solutions on previously marked skin
areas, which should be at least 4 cm apart. Puncture with a needle or blood
lancet through the test solution. There should be no bleeding. (If the
needle/lancet is re-used in an individual patient, it should be wiped thoroughly
between tests to avoid carry-over of allergen.)
Blot excess fluid from the arm, taking care not to cross contaminate the test
The test(s) should be accompanied by a negative control test with the solvent
used for the extracts. (A positive control test with histamine solution may also
Interpretation of skin test reactions
Scrutinise the course of reactions at intervals. The definitive test result is read
after approximately 10 minutes. A positive control test reaction presents as a
pale wheal (oedema) with a surrounding halo of red (erythema).
Assess the strength of each reaction by the degree of erythema and the area of
the wheal formed. Record the strength of each reaction relative to the control
as follows:- No wheal. Erythema absent or less than 1 mm diameter.
+ Wheal absent or very slight. Erythema present, not more than 3 mm
++ Wheal not more than 3 mm diameter, with associated erythema.
+++ Wheal between 3 mm and 5 mm diameter, with erythema.
++++ Any larger reaction, possibly with pseudopodia.
Although some patients will give a reaction to the control solution, they will
usually give significantly larger reactions to the allergens to which they are
clinically sensitive. In recording the reactions to these allergens, an allowance
should be made for the size of the control solution.
Prick testing solutions must not be used for intradermal testing.
The prick test solutions must not be used in the presence of any of the
conditions listed below:
Any skin lesions in the area to be used for testing.
Any diseases seriously affecting the patient’s general condition.
Hypersensitivity to any of the excipients listed in Section 6.1.
Pregnancy – please refer to Section 4.6 Fertility, Pregnancy and lactation.
Special warnings and precautions for use
Skin tests should not be performed during treatment with betablockers.
An emergency medical kit and adrenaline/epinephrine should always be kept at hand
when giving any prick test.
Using a needle/lancet, or a rinsing solution, for more than one patient carries the risk
of transmitting blood-borne viruses, and must not occur.
The patient should be instructed not to rub or scratch the test site.
Systemic anaphylaxis following prick testing is almost unknown. The operator should
have adequate experience to differentiate anaphylactic reaction from other reactions
more likely to be seen during skin testing, e.g. vasovagal, hyperventilation etc, and to
manage those reactions appropriately.
Warning symptoms include:
Tingling, itching and burning sensations on the tongue, in the mouth, throat or
particularly on the palms and soles. This may be immediately followed by shock with
cyanosis, hypotension, tachycardia, bronchospasm and unconsciousness.
Further clinical signs are: anxiety, restlessness, urticaria, dizziness, laryngeal oedema
with dyspnoea, nausea and vomiting, respiratory and cardiac arrest.
Severe and potentially life-threatening reactions require fast and effective emergency
The treatment of allergic reactions is based on current medical guidelines.
Interaction with other medicinal products and other forms of interaction
Used as concomitant therapy with anti-allergic agents like antihistamines,
corticosteroids and medicines with an incidental antihistamine action, this
solution for skin prick test may cause false negative results. As such,
medicines should be discontinued at least 48 hours – and Astemizole 6-8
weeks – before testing.
Fertility, pregnancy and lactation
Skin testing should not be carried out during pregnancy.
Skin testing may be carried out during lactation.
There are no fertility data available. No effects on fertility are anticipated.
Effects on ability to drive and use machines
D.farinae 10,000 DU/ml has no influence on the ability to drive and use
Adverse allergic reactions are rarely encountered during skin prick testing. Patients
should be warned that late local reactions may occur and that they are no cause for
concern and can be treated with oral antihistamine or topical corticosteroid.
In certain circumstances unduly severe or prolonged reactions may occur in patients
who have a high degree of sensitisation. In exceptionally rare cases there may be
generalised adverse reactions even amounting to serious systemic reactions
(anaphylactic shock). For these reasons an ‘emergency kit’ (with an
adrenaline/epinephrine syringe) must be immediately available. As a precautionary
measure, each patient must be kept under observation for at least 30 minutes, after
which time a medical assessment is made.
Local: - Such as swelling or irritation. These may require symptomatic treatment if
they are severe or persist.
Systemic:Mild: such as rhinitis or urticaria.
Severe: Such as wheezing or bronchospasm.
Anaphylactic shock can develop a few minutes after administration, often before a
local reaction has appeared (see section 4.4).
Typical warning symptoms of anaphylactic shock are described in section 4.4.
In exceptionally rare cases, adverse reactions may occur even a few hours after
exposure to the allergen. When in doubt especially after the appearance of systemic
reactions the patient should seek medical advice / treatment immediately.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is
important. It allows continued monitoring of the benefit /risk balance of the medicinal
product. Healthcare professionals are asked to report any suspected adverse reactions
via the Yellow Card Scheme Website: www.mhra.gov.uk/yellowcard
If the product is used incorrectly (e.g. intracutaneous use), allergic reactions may be
more severe. In such cases, the risk of anaphylactic shock is increased.
Pharmacotherapeutic group: Allergens
ATC Classification: V04C L Tests for allergic diseases
In an antigen-antibody reaction, the allergens present in prick test solutions
react with allergen-specific IgE sensitised mast cells in the patient’s skin. This
reaction liberates mediators, in particular histamine, from the mast cells.
These produce erythema at the test site, together with a demarcated weal,
sometimes accompanied by the formation of pseudopodia.
Preclinical safety data
No further information of relevance.
List of excipients
Water for Injections
Special precautions for storage
Store in a refrigerator (2ºC - 8ºC).
Do not freeze.
Nature and contents of container
2.0ml Type 1 Ph.Eur. glass dropper container with polyethylene screw cap
with pipette and black rubber teat
Special precautions for disposal
No special requirements for disposal
Any unused medicinal product or waste material should be disposed of in
accordance with local requirements.
MARKETING AUTHORISATION HOLDER
Allergy Therapeutics (UK) Ltd
MARKETING AUTHORISATION NUMBER
DATE OF FIRST AUTHORISATION/RENEWAL OF THE
29 September 1999
DATE OF REVISION OF THE TEXT