A 1 year old male neutered DSH presented for a few week history of lameness and swollen paw pads. A general physical examination revealed swelling and ulcerations on all four paws (metatarsal pads, metacarpal pads and digital pads). The lower lip also appeared to be swollen (see images below). No evidence of fleas or other ectoparasites were seen and the rest of the physical examination was unermarkable. Very mild improvement was seen with antibiotic treatment over the next couple of weeks. Due to the lack of improvement, the cat was then anesthetized and biopsies of his paw pads were taken and submitted to the lab. The biopsies revealed a diagnosis of eosinophilic granuloma. He was treated with a long acting steroid injection and showed dramatic improvement. Three weeks later a second steroid injection was given, and within two weeks the paw pads had completely resolved and the lip swelling had gone down. The underlying cause is still unknown, but the owners are planning to pursue a hypoallergenic diet and possible allergy testing if there is recurrence.
FELINE EOSINOPHILIC GRANULOMA COMPLEX
Eosinophilic granuloma complex is a commonly seen syndrome/reaction pattern in cats. There are three clinically distinct presentations: 1. Eosinophilic granulomas, 2. Indolent/rodent ulcers, 3. Eosinophilic plaques. Combinations of different forms can be seen in an individual cat.
Rather than being a primary problem, eosinophilic granuloma complex is usually a secondary reaction pattern to an underlying issue. Underlying problems for this syndrome include: ectoparasites (i.e. fleas), food or environmental allergies, or idiopathic (unknown cause).
The eosinophilic granuloma is a lesion that can occur on the skin, mucocutaneously or in the oral cavity. Most commonly the lesions occur on the caudal thighs, face and the oral cavity. On the face, the lesions are often nodular in appearance and cause lip and chin swelling. On the thighs the granulomas are often linear. The patient is commonly non-pruritic.
Indolent ulcers are commonly found on the skin, mucocutaneously or in the oral cavity. Most commonly the lesions are found on the upper lip (unilateral), but they can also occur bilaterally, especially when found in the oral cavity or on skin. Most commonly eosinophilic plaques occur on the abdomen and medial thighs. Single or multiple lesions can occur and patients are usually severely pruritic. The lesions are usually round, well circumscribed and often ulcerated.
The clinical signs are very characteristic but cytology and biopsy are diagnostic if necessary.
The prognosis and long-term management depend on the underlying cause. Finding the underlying cause can be difficult and may involve food trials and/or allergy testing. However, many cases are idiopathic and require symptomatic treatment for flare-ups. Some lesions may be refractory to treatment, while others may resolve spontaneously.
Patients with eosinophilic granuloma complex lesions will often be treated with steroids and other immunosuppressive drugs if non-responsive to steroids.