Small Animal Dermatology, 3rd edition

354 DISEASES/DISORDERS

 Atopy: intradermal testing (preferred) or serum testing followed by allergen-specific

immunotherapy.

 Dermatohistopathologic diagnosis: required for definitive diagnosis and distinguish-

ing the EGC syndromes:

Eosinophilic plaque: severe epidermal and follicular spongiosis and mucinosis

with eosinophilic exocytosis; intense perivascular to diffuse dermal eosinophilic

infiltrate; eroded or ulcerated epidermis

Eosinophilic granuloma: epidermal acanthosis with scattered apoptotic ker-

atinocytes; distinct foci of eosinophilic degranulation and collagen degeneration

(“flame figures”); nodular to diffuse granulomatous inflammation; eosinophilic

and giant cell infiltrate

Indolent ulcer: severe ulceration of the epidermis or mucosa with fibrosing

dermatitis and neutrophilic inflammation; significant eosinophilic infiltration

unusual

Allergic miliary dermatitis: discrete foci of epidermal erosion and necrosis with

brightly eosinophilic crusts; dermal perivascular to interstitial eosinophil-rich

infiltrate.

 CEG (dog): foci of palisading granulomas and flame figures surrounding collagen

fibers; eosinophilic infiltrate mixed with multinucleated giant cells, macrophages,

reactive mast cells, plasma cells, and lymphocytes.

THERAPEUTICS

General Considerations: Cats

 Adequate flea control measures paramount to manage a majority of cases.

 Outpatient unless severe oral disease prevents adequate fluid intake.

 Identify and eliminate offending allergen(s) before providing medical intervention.

 Allergen-specific immunotherapy in cats with atopic dermatitis; successful in a major-

ity of cases; preferable to long-term corticosteroid administration.

 Deter patient from damaging lesions by excessive grooming with behavior modifica-

tion techniques and/or distraction.

General Considerations: Dogs

 Individual lesions may be surgically excised or ablated via CO 2 laser if being mechan-

ically traumatized and medically unresponsive.

Drugs of Choice

 Eosinophilic plaque and indolent ulcer: may improve with antibiotics: trimethoprim-

sulfadiazine 10–15 mg/kg PO BID, cephalexin 22 mg/kg PO BID, amoxicillin

trihydrate-clavulanate 12.5 mg/kg PO BID, or clindamycin 5.5 mg/kg PO BID.