Issue Description Discoid Lupus Erythematosus (DLE) is a skin
condition of dogs that typically causes a loss of color
(discoloration) on the hairless part of the nose. A black nose may
fade to gray or pink. The discoloration can be accompanied by ulcers
and bleeding. The surrounding skin may also be effected. Other Names Collie Nose, Canine Discoid Lupus Erythematosus, DLE
Commonly Affected Breeds
German Shepherd Dog
German Shorthaired Pointer
Symptoms The most common initial symptom is scaling and
loss of pigment on the nose. This is found in up to 90 percent of
dogs. The surface of the nose becomes smooth gray, and ulcerated,
instead of the normal black cobblestone texture. Over time the lips,
the skin around the eyes, the ears, and the genitals may become
involved. Lesions may progress to ulceration and lead to tissue
destruction. DLE is often worse in summer due to increased sun
Diagnosis DLE is easily confused with solar dermatitis,
pemphigus, ringworm, and other types of dermatitis. Biopsy is required
to make the distinction. Histopathologically, there is inflammation at
the dermoepidermal junction and degeneration of the basal cell layer.
Unlike in SLE, an anti-nuclear antibody test is usually negative.
Treatment Avoiding sun exposure and the use of sunscreens
(not containing zinc oxide, which is toxic to dogs) is important.
Topical therapy includes corticosteroid use. Oral vitamin E or omega-3
and omega-6 fatty acids are also used. More refractory cases may
require the use of oral niacinamide and tetracycline, corticosteroids,
azathioprine, or chlorambucil. Treatment is often lifelong, but there
is a good prognosis for longterm remission.