470 DISEASES/DISORDERS
Perioral and periocular skin often affected (Figure 31.8).
Perinasal region, nasal planum, and oral mucosae may be affected.
Hyperpigmentation at periphery of lesions.
VCLE
Formerly considered a variant of dermatomyositis or hidradenitis suppurativa.
Involves medial thigh, groin, axillae, and ventral abdomen.
Mucocutaneous junctions often affected.
Lesions seen as serpiginous or polycyclic ulcerations.
ECLE
Fine adherent scales and alopecia starting on the muzzle and pinnae (Figures 31.9,
31.10).
Lesions generalize to include entire body and extremities (Figure 31.11).
Lymphadenopathy and pyrexia common.
Often associated with lameness, stiffness, and pain.
SLE
Cutaneous lesions characterized by erythema, erosion, and ulceration (Figures
31.12–31.14).
Mucocutaneous and oral lesions common.
Ulcerations of the lateral aspect of the tongue.
Joints often swollen and painful.
Fever, lymphadenopathy, hepatosplenomegaly, muscle wasting, myocarditis, peri-
carditis, pleuritis.
DIFFERENTIAL DIAGNOSIS
Other immune-mediated diseases: pemphigus foliaceus, pemphigus erythematosus,
mucous membrane pemphigoid, and uveodermatologic syndrome.
Drug reactions, erythema multiforme, and toxic epidermal necrolysis: nasal and facial
lesions.
Mucocutaneous pyoderma; differentiated from LE by complete response to antibi-
otics.
Dermatomyositis: affects some of the same predisposed breeds (collies and Shetland
sheepdogs).
Nasal pyoderma and nasal dermatophytosis: infectious conditions; can mimic DLE.
Insect hypersensitivity (eosinophilic furunculosis).
Contact allergy.
Zinc-responsive dermatosis.
Superficial necrolytic dermatitis.