What It Is:
Eosinophilic Granuloma Complex, or EGC, is a group of inflammatory skin conditions in cats that involve an abnormal response by the immune system. It is not a single disease, but a collection of related lesions that typically affect the skin, lips, mouth, thighs, or belly.
The three main forms of EGC are:
- Eosinophilic granuloma
- Eosinophilic plaque
- Indolent ulcer (also called rodent ulcer)
These lesions are often caused by allergies, including flea allergies, food sensitivities, or environmental triggers.
🐾 Common Symptoms
Symptoms depend on the type of lesion and its location:
- Raised, pink or yellow plaques on the belly or thighs
- Raw, red, or oozing skin
- Ulcers or sores on the upper lip or inside the mouth
- Firm, linear swellings on the back of the thighs
- Hair loss or scabbing around lesions
- Licking, chewing, or scratching the affected area
- Pain or difficulty eating if oral lesions are present
Lesions may appear suddenly, then improve and return over time.
🦠 Causes and Risk Factors
EGC is most commonly triggered by allergic reactions, especially:
- Flea bites (most common cause)
- Food allergies
- Environmental allergens such as pollen, dust, or mold
- Insect bites
- Contact allergies to cleaning products or materials
Less commonly, lesions may be associated with bacterial infection, viral infections, or genetic predisposition.
Certain breeds such as Siamese or Oriental cats may be more prone to developing EGC.
🔍 Diagnosis
Diagnosis is usually based on the appearance of the lesion and ruling out other skin diseases.
Steps may include:
- Physical exam and history of symptoms
- Skin scraping or cytology to look for infection or abnormal immune cells
- Biopsy if the lesion does not respond to treatment
- Allergy testing or food elimination trials if allergic cause is suspected
- Flea control assessment to rule out flea allergy dermatitis
EGC lesions are not cancerous, but they can look alarming and may resemble other conditions.
💊 Treatment
Treatment aims to reduce inflammation, resolve the lesion, and manage the underlying allergy.
Options include:
- Flea control with year round, fast acting preventatives
- Steroids such as prednisolone to reduce inflammation and immune response
- Antibiotics if a secondary bacterial infection is present
- Immunomodulatory drugs for long term control in recurrent cases
- Food trials with hypoallergenic diets
- Antihistamines or omega 3 supplements to reduce itchiness
- Topical medications for small or localized lesions
Some cats require long term management, especially if the underlying cause cannot be fully identified.
🩺 Prognosis
With proper treatment, most lesions resolve quickly:
- Isolated cases often respond well to short term treatment
- Chronic or allergic cases may need long term or repeated treatment
- Identifying and controlling the underlying allergy is key to long term success
Relapses are common if treatment is stopped too early or triggers are not removed.
💡 Cat Owner Note
Those weird pink patches on your cat’s belly or that sore on the lip might not be a wound or infection. They could be part of eosinophilic granuloma complex. The name sounds scary, but treatment is usually simple once your vet pinpoints the cause.
❓ Frequently Asked Questions About EGC in Cats
Is eosinophilic granuloma complex contagious?
No. EGC is not contagious to other animals or people.
Can EGC go away on its own?
Sometimes, but treatment is usually needed to reduce inflammation and prevent complications.
What causes EGC in cats?
Most often, it is caused by an allergy — usually to fleas, food, or something in the environment.
Will my cat need medication forever?
Not always. Some cases resolve after a single treatment, while others require long term management.
Is EGC the same as cancer?
No. EGC is an inflammatory condition, not a cancer. However, biopsy may be needed to rule out more serious diseases.
How do I prevent EGC from coming back?
Control fleas year round, identify and avoid allergens, and monitor for early signs of recurrence.