Mosquito Bite Hypersensitivity in Cats

A severe mosquito bite hypersensitivity in cats will require prompt veterinary care, but mild cases often resolve without the use of medical treatment. Mosquito bite hypersensitivity in cats can resemble a number of harmful health conditions including herpesvirus and infection, so a veterinary-performed differential diagnosis is crucial.

Mosquito bite hypersensitivity in cats is a visually distinctive allergic skin disease associated with the bite of a mosquito. This relatively uncommon skin condition will cause the feline to develop a crusted, ulcerated dermatitis reaction isolated to the nose or pinnae (ear tip). Commonly recognized by pruritus, or itching of the skin, mosquito bite hypersensitivity can cause localized swelling, hair loss, and a change in skin color. 

Mosquito bite hypersensitivity will cause the feline to develop a crusted, ulcerated dermatitis reaction isolated to the nose or pinnae (ear tip). Although the lips, chin, eyelids, and footpads can also be affected, these areas are not common sites of reactions. The sustained bite transforms from a lesion to a wheal that progressively becomes a crusted ulcer in the affected area. This hypersensitive reaction is commonly recognized by pruritus, or itching of the skin, but additional symptoms of mosquito bite hypersensitivity in cats can include: 

• Lymphadenopathy (swollen lymph nodes) 
• Fever 
• Alopecia 
• Change in skin pigment/coloration
• Localized swelling

Mosquito bite hypersensitivity in cats is caused by a hyperactive response from the immune system. The immune system is designed to detect and destroy harmful invaders that come in contact with the body. The feline’s immune defense attacks these foreign invaders by creating specialized antibodies to engulf the allergen. These antibodies trigger the body’s various types of white blood cells, which have an inflammatory response causing the swelling, itching, and redness associated with an allergy.

Feline mosquito bite hypersensitivity is common in geographical areas with mosquito-endemic environments. Cats of any age and breed can be affected by mosquito bite hypersensitivity, but purebred cats have a higher rate of occurrence. 

The veterinarian will perform a differential diagnosis to rule out other common allergy-causing sources such as dermatophytosis, notoedric mange, and other causes of eosinophilic dermatitis (idiopathic, atopy). The doctor will also want to rule out the possibility of contracted herpesvirus and pemphigus foliaceus before coming to the conclusion of a mosquito bite hypersensitivity in the feline. A skin biopsy is a common diagnostic procedure used to determine the nature of the affected area. If the tests come back negative, the doctor may ask to have the cat isolated indoors for about a week to note if her condition has improved. The symptoms your cat presents, and the season and lifestyle of your cat (outdoors cat) will suggest an insect bite related reaction.

The mosquito bite hypersensitivity in the affected cat will resolve without treatment if the feline is isolated from the contributor. The veterinarian may inject the feline with a corticosteroid to reduce the hypersensitive response and provide comfort for the feline. Topical creams may also be placed on the ulcerated area to improve healing time and reduce scratching the area. An Elizabethan collar may be advised if the feline is manipulating the area profusely, causing bleeding which may result in a skin infection. 

If your feline is experiencing a severe hypersensitive reaction to the mosquito bite, the veterinarian may prescribe the use of a systemic glucocorticoid or corticosteroid. An immunosuppressant or antihistamine may also be a treatment choice for your cat if the condition is long-lasting. Some felines require drug therapy for the duration of mosquito season to combat the hypersensitive reaction. Ask your veterinarian about treatment options for mosquito bite hypersensitivity in cats, as holistic options may be available. 

The veterinarian will advise cat owners to keep their hypersensitive feline indoors when warm weather brings the presence of mosquitoes. If the mosquito exposure is anticipated, a pyrethrin repellent may be used to prevent mosquitoes from biting. You can decrease the mosquito population inside your home by placing screens on the doors and windows of your home. An automatic mosquito spray device can also aid in the elimination of indoor mosquitoes, but make sure the cat cannot reach the device, as direct exposure can be toxic. Outdoors, avoid standing water sources as mosquitoes are attracted to water. You can also use a bug zapper and mosquito candles to deter mosquitoes from entering your yard.