Eosinophilic Granuloma Complex (EGC) refers to a group of inflammatory skin conditions that occur in cats. These lesions are caused by an overactive immune response—often triggered by allergies—and can appear anywhere on the skin or in the mouth. While the name sounds intimidating, most cases can be managed successfully with proper diagnosis and treatment.
“Eosinophilic” refers to a type of white blood cell involved in allergic reactions and inflammation. When these cells accumulate in the skin, they form visible lesions or ulcers. The term “complex” means there are several possible forms of the same underlying process.
2. Indolent (Rodent) Ulcer – Firm, well-defined ulcer on the upper lip, usually not painful but may worsen over time. Can be single or occur on both sides of the lip.
3. Eosinophilic Granuloma (Linear Granuloma) – Firm, yellow-pink raised line or lump, often found on the back of the thighs, face, or mouth. Sometimes seen in younger cats.
Most EGC lesions are caused by allergic triggers, including:
• Flea allergy dermatitis (most common cause)
• Food allergies
• Environmental allergies (dust, pollen, molds)
Less commonly, genetics, parasites, or foreign materials in the skin may play a role. Because allergies are chronic conditions, EGC often recurs unless the underlying cause is identified and controlled.
Diagnosis usually includes:
• Physical examination and review of your cat’s history
• Cytology or biopsy to confirm eosinophilic inflammation
• Allergy testing or elimination diet trials to identify triggers
• Flea control assessment (every allergic cat must be on strict flea prevention year-round)
Treatment depends on the severity and underlying cause:
Flea control: Revolution Plus or another veterinarian-approved product is essential.
Corticosteroids or other anti-inflammatory medications: Help reduce inflammation and itching.
Antibiotics or topical therapy: Used if secondary infection is present.
Allergy management: Food trials or allergy medications (such as Atopica or Apoquel in cats) may be needed long-term.
Environmental management: Reduce exposure to allergens where possible.
Some cats require ongoing maintenance therapy to prevent flare-ups.
Follow-up visits are important to:
• Re-evaluate the skin or mouth as lesions heal
• Adjust medications safely
• Confirm that secondary infections have resolved
• Identify any new or persistent triggers
Even when lesions clear, continuing allergy prevention—especially flea control—is key to preventing recurrence.
Call us if you notice:
• New sores or swelling on the lips, skin, or inside the mouth
• Excessive licking or scratching
• Any recurrence after treatment
Early attention can help avoid discomfort and prevent long-term scarring.
Our team at The Cat Hospital of Media is experienced in diagnosing and managing feline skin and allergy conditions. We’ll work with you to keep your cat comfortable and minimize flare-ups long-term.
