Small Animal Dermatology, 3rd edition

(Tina Sui) #1

CHAPTER 31 LUPUS ERYTHEMATOSUS 471


 Dermatophytosis.


 Metabolic epidermal necrosis.


 Epitheliotropic lymphoma: may start on the planum and rostral aspect of the muzzle


and lips.


 Squamous cell carcinoma: may affect the planum; may occur at a slightly higher inci-


dence in chronic discoid lupus lesions.


 Idiopathic leukoderma leukotrichia (vitiligo): may cause depigmentation of the tissue


and hair without concurrent inflammation.


 Neoplasia-induced vasculitis.


 Infectious diseases must be differentiated from SLE.


DIAGNOSTICS


 CBC/biochemistries: usually normal; thrombocytopenia in 25% of cases of ECLE.


 ANA, LE preparation, and Coombs tests: usually normal or negative except with SLE.


 SLE: nonerosive polyarthritis, proteinuria from glomerulonephritis, hemolytic ane-


mia, leukopenia, thrombocytopenia, polymyositis, high concentration of beta and
gamma globulins on serum electrophoresis.

 Dermatohistopathology from biopsy:
DLE: lymphocytic interface lichenoid dermatitis with pigmentary incontinence,


prominent basal cell apoptosis, variable degrees of dermal mucin and epidermal
atrophy
GDLE: more severe (than DLE) lymphocytic interface dermatitis with basal cell

degeneration; suprabasal and lymphocytic satellitosis of apoptotic basal cells;
pigmentary incontinence, basement membrane thickening
MCLE: lymphocytic interface lichenoid dermatitis with pigmentary inconti-

nence, prominent basal cell apoptosis; basement membrane thickening; erosions
and ulcerations without blistering; changes most prominent at ulcer margins
VCLE: lymphocytic interface dermatitis with dermoepidermal junction vesicu-

lation; basal cell apoptosis
ECLE: lymphocytic interface dermatitis extending into follicular infundibulum

and sebaceous glands; mural folliculitis; basal cell apoptosis
SLE: lymphocytic interface dermatitis with pigmentary incontinence and

basal cell apoptosis; subepidermal vesiculation; leukocytoclastic vasculitis;
panniculitis.

 Direct immunofluorescence or immunohistochemistry staining may reveal


immunoglobulin and complement deposition at the dermoepidermal junction.


THERAPEUTICS


Drugs of Choice


 Cycline antibiotics: tetracycline (250 mg PO TID for dogs<10 kg; 500 mg PO TID


dogs>10 kg); doxycycline (10 mg/kg PO q24h); minocycline (5 mg/kg PO BID); often

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