What is mosquito bite hypersensitivity?
Mosquito bite hypersensitivity is a relatively common disease in cats that occurs during the summer months in warm climates.  It is an overreaction of the cat’s immune system to a mosquito bite.  In the case of hypersensitivity the immune system basically does not know when to quit battling the foreign body and this causes a more severe problem that the mosquito bite itself.

What does mosquito bite hypersensitivity look like?
The most typical  lesions are areas of crusts scaling and raw ulcers.  These lesions most commonly occur on the ears and nose.  Long-term cats may develop hair loss and pigment changes in the affected area.  In many cases the pads of the feet will be thickened tender swollen and red and may have fissures.  Some cats may have a slight fever and swollen lymph nodes.

How is mosquito bite hypersensitivity diagnosed?
Mosquito bite hypersensitivity can look like many other skin ailments commonly found in cats including ringworm food allergy eosinophilic plaque cancer and bacterial infections.  Therefore the diagnosis of mosquito bite hypersensitivity is based on the signs of the disease season of the year biopsy results and improvement of the lesions when the cat is confined to a mosquito-free area for a minimum of 4-7 days.

How is mosquito bite hypersensitivity treated?
Mild cases will resolve on their own if the cat is isolated from mosquito contact.  More severe mosquito bite hypersensitivity is treated with corticosteroids either by injection or oral administration.  Dexamethasone is one example of an orally-administered drug containing corticosteroids to help reduce pain inflammation and other side effects of mosquito bite hypersensitivity.  However it is only available through a prescription.

How is mosquito bite hypersensitivity prevented?
Prevention is based on limiting the animal’s exposure to mosquitoes.  Mosquito control is essential.  Keeping cats indoors is extremely helpful especially during times of the day when mosquitoes are most active – namely dawn and dusk.  Also insect repellents which contain pyrethrin can be used such as Adams Flea & Tick Mist or Bio-Groom Flea & Tick Spray or Vetscience Flea & Tick Mist.