Options for Feline Eosinophilic Lesions

Feline eosinophilic granuloma complex (EGC) is not a specific dermatologic diagnosis, but is seen with a number of distinct clinical entities. Most authors recognize that EGC is a manifestation of allergic disease, although other causes have been suggested. Infectious agents have been proposed to be involved, but the role of bacteria is likely secondary. Cytologic and histopathologic examination are recommended. Atopic disease should be considered when other primary diseases have been ruled out, especially ectoparasitic disease and cutaneous reactions to food. Most EGC cats appear clinically well; if they show signs, other disease problems should be investigated. Systemic glucocorticoids are often used with good response, but high doses may be needed. Depot cortico-steroids should be avoided. Cyclosporine is very effective at doses ranging from 3.6–13.3 mg/kg q24h. If good response is seen after 4 weeks, treatment can be tapered to alternate day and then twice weekly therapy. Concerns about toxoplasmosis and cyclosporine appear to be minimal at doses ≤7.5 mg/kg q24h. Hydrocortisone aceponate, a topical product licensed for dogs in some countries, also appears to be useful in treating EGC in cats. Chlorambucil has been used in cases refractory to steroid treatment. Anecdotal reports suggest that interferon omega can be effective and well tolerated in some cats with EGC lesions. 

CommentaryFeline EGC can be frustrating to treat; although allergies may be an underlying cause in cats, other triggers may play a role as well. Because many dermatologic conditions feature secondary infections, and because the skin reacts in limited ways to various stimuli, a step-wise approach is indicated. This article succinctly described the diagnostic plan for approaching cats with eosinophilic lesions. The discussion on treatment options beyond steroids is particularly helpful, as these lesions can frequently be controlled with nonsteroidal therapies. Some of the treatments mentioned, however, might not be available in all countries.—William Oldenhoff, DVM

SourceFeline eosinophilic granuloma complex(ities) some clinical clarification. Buckley L, Nuttall T. J FELINE MED SURG 14:471-481, 2012.