Page 1013 - Veterinary Immunology, 10th Edition

reaction to intradermally injected flea antigen. Most sensitive
VetBooks.ir animals will respond within a few minutes, but up to 30% may

show a delayed reaction at 24 to 48 hours. Hyposensitization
therapy has not been shown to be successful in treating flea allergy.

Flea allergy can be successfully treated only by total flea control.

Eosinophilic Granuloma Complex

The eosinophilic granuloma complex is a group of diseases

associated with various types of skin lesions (i.e., ulcer, plaque,
granuloma) in cats. Although their cause is unknown, they have
been associated with flea or food allergies or atopic dermatitis. The
presence of eosinophils in skin is often associated with the
development of pathological lesions (Fig. 30.11). Thus when

purified eosinophil cationic protein (ECP) or eosinophil-derived
neurotoxin (EDN) are injected into guinea pig or rabbit skin, they
disrupt skin integrity and cause inflammation. ECP produces

ulcers, whereas EDN produces cellular exudates. Purified
eosinophil peroxidase and the chemokine MBP-1 produce
induration and erythema. The activities of these proteins may
explain the development of lesions in eosinophil-associated skin
diseases.

FIG. 30.11 An eosinophilic granuloma on the footpad of a dog.
(Courtesy Dr. R. Kennis.)

A seasonal eosinophilic lesion in cats has been associated with
mosquito bites. This may present as scattered individual crusted
papules. The eosinophilic plaques in the skin are intensely pruritic.

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