Felis catus hair

Studies have shown that skin tests with cat extract are useful in the diagnosis of cat allergy. As a rule, persons with cat allergy have positive skin reactions when tested with cat extract, and non-allergic individuals rarely react. However, the relationship between a positive skin test and the appearance of clinical symptoms after exposure to a cat is not absolute, i.e., some skin-test positive persons do not experience allergic symptoms after exposure. Failure to experience symptoms may be dose related, since it is known that cats vary significantly in the amount of Fel d1 they produce. The efficacy of cat extract immunotherapy in the treatment of bronchial asthma has been shown in two studies. A reduction in bronchial sensitivity was observed in five patients with cat allergy, whereas no reduction was observed in placebo treated, cat-allergic patients.

Diagnosis: Concentrated extract (10,000 BAU/mL) may be used for scratch or prick-puncture testing. Puncture tests performed with a bifurcated needle in ten cat allergic persons showed a mean wheal diameter of 6.6 mm (S.D. 1.3) with a mean sum of erythema of 57.3 mm (S.D. 10.4). Intradermal tests with serial three-fold dilution of the 10,000 BAU/mL showed the following results: Serial 3-Fold Dilutions of 10,000 BAU/mL Extract Subject 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1 X 2 X 3 X 4 X 5 X 6 X 7 X 8 X 9 X 10 X The mean three-fold dilution eliciting a response of 50 mm sum of erythema diameters was 11.120 (S.D. 2,38). The number of BAU/mL required to elicit this response was 0.05 (range 0.0003 to

Standardized Cat Hair Extract should not be used for immunotherapy in persons who do not have cat related allergic symptoms and a positive skin test to the extract.

This allergenic product is intended for use 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. Standardized Cat Hair Extract may cause local or severe life-threatening reactions when administered to highly sensitive individuals. Physicians who use this product should be familiar with the clinical use of allergenic extract and have the necessary emergency equipment and medications available to treat systematic allergic reactions See Precautions, Adverse Reactions and Overdosage.

Local Reactions From Skin Testing Large local reactions may result from skin tests with Standardized Cat Hair Extract. To help prevent this, a patient should be skin tested initially by the prick or scratch method. If a positive response is NOT observed, an intradermal skin test may be performed with a more dilute solution of the extract. Oral antihistamines and topical corticosteroids may be administered to relieve itching and swelling resulting from large skin test reactions. Local Reactions From Subcutaneous Injections The occurrence of a hive 5 to 15 minutes after the subcutaneous injection of extract is usually due to leakage of extract into the skin along the needle tract. Firm pressure (not rubbing) at the site of injection immediately after withdrawal of the needle will usually prevent this reaction. It does not require a reduction in dosage.

Extract should be stored at 2°C to 8°C since higher temperatures may adversely affect stability. Do not freeze.