According to professional data analysis, the allergen for cat allergy is actually a protein, mostly present in dander, saliva, and urine. Because the particle size of these cat allergens is extremely small, cat allergens usually spread through the air as microscopic particles, inhaled by allergy sufferers, and can remain airborne for a long time. Allergens are foreign particles such as cat dander, pollen grains, dust particles, and enzymes from dust mite feces. Allergic people tend to be sensitive to more than one substance. Allergic reactions depend on the amount of allergen in the environment and the individual's sensitivity to these allergens. Symptoms of cat allergy include asthma. Pollen allergy, sneezing, the most common, possibly accompanied by a runny or blocked nose. Itching of the eyes, nose, and throat.

Common allergic diseases include urticaria, clinically manifested as sudden appearance of pink raised blisters of varying sizes on the skin, mostly round, which can occur anywhere on the body; initially existing singly, gradually expanding and developing into patches. Urticaria usually appears and disappears quickly, coming and going. Some people also experience gastrointestinal reactions such as abdominal pain and diarrhea. Severe patients may also develop heart-related diseases.

Allergic rhinitis is clinically mostly manifested by sudden itching inside the nostrils and continuous sneezing. Allergic shock is clinically manifested by mucosal flushing initially appearing on the patient’s skin surface, mostly large wheals, with extensive dermal and subcutaneous vascular edema. Another condition is hay fever, which has very obvious seasonality and regional characteristics, mostly manifesting as itchy eyes and swollen eyelids; watery secretions increase after sneezing, and some patients may have wheezing heard during auscultation.

The last and also a relatively common one is allergic asthma, mostly characterized by sudden onset or worsening symptoms, paroxysmal expiratory dyspnea, and wheezing, usually lasting several hours. Before onset, there are often sneezing, runny nose, cough, and other mucosal allergy precursors.