Phadia’s E1 test is used to detect blood levels of the IgE (antibodies) responsible for allergic reactions (sneezing, runny nose, watery eyes, asthma attack) to cat epithelium (dandruff or dander). The interpretation chart accompanying the results expresses the probability of an allergic reaction to cat epithelium, but not necessarily the severity of the reaction. Case history (symptoms, connection to contact with animals such as dogs, cats, horses, etc.) and clinical examination by the physician are essential for a reliable interpretation of the results.
An anti-cat epithelium IgE result below 0.35 kilounits per litre (< 0.35 kU/L) indicates that cats are probably not responsible for the symptoms reported by the person, but it DOES NOT COMPLETELY RULE OUT THIS POSSIBILITY. All negative and positive results must be interpreted in light of the case history. Some individuals are only allergic to cats while others are also allergic to dogs or horses. Tests measuring IgE against specific molecular cat, dog or horse allergens can be used to determine if an individual is specifically allergic to one or more types of animal (co-allergy vs. cross allergy).