Feline Eosinophilic Granuloma Complex
What is feline eosinophilic granuloma complex?
Eosinophilic granuloma complex is a term used to describe three forms of skin lesions in cats: eosinophilic plaque, eosinophilic granuloma and indolent ulcers. . These lesions have a characteristic microscopic appearance due to the presence of eosinophils, which are a form of inflammatory cell. The term eosinophilic granuloma is derived from the presence of these cells.
What causes eosinophilic granuloma complex?
The exact cause of feline eosinophilic granuloma complex is not known. Research suggests that some form of allergic response may be involved (hypersensitivity reaction) in the majority of cases. This is more likely in cases that are recurrent. Other studies seem to indicate that the condition may at least be partially genetic or inheritable.
What are the symptoms of feline eosinophilic granuloma complex?
The most common site for these lesions is on the lips, especially the upper lips, where they appear as ulcers. They are sometimes referred to as "rodent ulcers” although this term is technically incorrect. The lesions range from small and barely noticeable ulcers to large and extensive ulcers with an obvious lip abnormality. Bleeding occurs from some lesions. Eosinophilic granulomas may also develop in the mouth, especially along the gums and palate, or on other areas of the body. When lesions form in other locations, they usually appear as bald patches with raised skin areas having a fleshy appearance rather than an ulcer. These types of lesions may also be referred to as eosinophilic plaques. Common sites are the hind legs and the stomach. The lesions can be large and may be itchy, since the cat frequently licks and even bites at the affected site.
How is eosinophilic granuloma complex diagnosed?
Diagnosis is based on your cat’s medical history and physical examination. Microscopic examination of a lesion (fine needle aspiration or biopsy and histopathology) is necessary to diagnose eosinophilic granulomas. The appearance of the characteristic lip ulcers is highly suggestive and biopsy may not be required initially. If lesions are located elsewhere on the skin or in the mouth, a biopsy is often recommended to rule out other diseases and conditions. Biopsy or fine-needle aspiration is a simple procedure that can be performed quickly and safely.
How is eosinophilic granuloma complex treated?
The most common treatment method for eosinophilic granuloma complex involves using corticosteroids. Corticosteroids can be given in a variety of different forms, but most often as injections or tablets. Treatment may last for weeks to months due to the fact that eosinophilic granulomas frequently recur and prolonged treatment will minimize the chance of recurrence. Side effects of corticosteroids are usually not significant in cats, but prolonged use can cause side effects such as an increase in weight.
There are numerous other treatments that may be used including other drugs, surgical removal of the lesions and cryosurgery or freezing of the lesions with liquid nitrogen while the cat is anesthetized. These treatments are sometimes recommended in recurrent cases. Some forms of eosinophilic granuloma complex are more difficult to treat. In cats with large skin lesions, surgery may be recommended early in the treatment course.
Flea and insect control is very important in the treatment of feline eosinophilic complex. This is due to the suspected hypersensitivity reaction cause of the condition. Insect bites can trigger an exaggerated immune response in affected cats, causing or worsening clinical signs.
Some cats respond to elimination or hypoallergenic diets, suggesting an underlying food allergy as the cause.
What is the prognosis for a cat diagnosed with eosinophilic granuloma complex?
Most cases respond well to medical treatment. Recurrence is common and requires life long intermittent treatment in many cases. Some cats that are severely affected will require more aggressive treatment and consultation with a board-certified veterinary dermatologist may be beneficial.