Management of Severe Cat Allergy
The most effective management for severe cat allergy is complete removal of the cat from the home, as this is the single most definitive intervention to reduce allergen exposure and improve symptoms. 1
Primary Approach: Allergen Avoidance
- Cat allergen (primarily Fel d 1) is found in cat skin/dander, saliva, and urine, and is common to all breeds of cats 2, 1
- Cat allergen particles are small and low-density, remaining suspended in air for extended periods and disseminating widely throughout homes 2
- Complete removal of the cat from the home is the most effective intervention 2, 1
- Be aware that cat allergen can persist for an average of 20 weeks after removal, so short trial removals may be misleading 1
If Complete Cat Removal Is Not Possible
If the patient refuses to remove the cat, implement these measures to reduce exposure:
- Confine the cat to an uncarpeted room away from the bedroom with HEPA filtration, which may reduce airborne allergen in the rest of the home by up to 90% 2, 1
- Keep the cat out of the patient's bedroom at all times 1
- Bathe the cat weekly to temporarily reduce airborne allergen levels 2, 1
- Place litter boxes in areas separated from the home's air supply 1
- Use high-efficiency air cleaners (central or portable) 1
Environmental Control Measures
- Use allergen-proof mattress and pillow encasings (less than 10 μm pore size) 1
- Wash bedding weekly in hot water (greater than 130°F) 2, 1
- Vacuum clean weekly using a vacuum with HEPA filtration 2, 1
- Replace upholstered furniture with leather, vinyl, or wood when possible 2, 1
- Replace carpets with polished wood flooring 1
- Replace draperies with washable shades or blinds 1
Pharmacologic Management
For patients with persistent symptoms despite environmental control:
- Second-generation oral antihistamines are preferred over first-generation antihistamines due to less sedation and anticholinergic effects 2
- For severe nasal symptoms, a short course (5-7 days) of oral corticosteroids like prednisone may be appropriate 2, 3
- For severe allergic reactions, epinephrine may be necessary (0.3-0.5 mg IM for adults and children ≥30kg, or 0.01 mg/kg for children <30kg) 4
Allergen Immunotherapy Considerations
- Allergen immunotherapy (AIT) may be considered for patients with persistent moderate-to-severe symptoms despite optimal pharmacotherapy and environmental control measures 5, 6
- Subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) are common routes of administration, with mixed results in clinical studies 5
- Depigmented, polymerized cat epithelium extract has shown favorable safety and effectiveness profiles in recent studies 6
Common Pitfalls to Avoid
- Assuming certain cat breeds are "hypoallergenic" - all breeds produce Fel d 1 allergen 1
- Short-term trial removal of cats (days or weeks) may be misleading due to persistent allergen 1
- Underestimating the persistence of cat allergen, which can remain at significant levels for months after cat removal 1
- Relying solely on isolated interventions like impermeable bedding without implementing multiple control measures 2, 1
- Failing to recognize that cat allergy can progress to asthma - patients exposed to cats developed asthma after a median of 24 months in recent studies 7