Canine Discoid Lupus Erythematosus (Collie Nose)
Aug
26
Written by:
8/26/2008
Discoid lupus erythematosus (DLE or collie nose) in canines (and rarely in felines) is an autoimmune skin disorder similar to discoid lupus in humans (see Overlapping Lupus Disorders). In canines, discoid lupus is limited to the skin, with the nose usually the first to be affected. Occasionally, the bridge of the nose, the lips, the skin around the eyes, the ears, and the genitals may be affected.
Symptoms
A loss of pigmentation is usually the first symptom. For instance, a black nose may redden or turn gray or pink. This loss of pigment is generally benign although it can increase the risk of squamous cell skin cancer.
The texture of the nose may also change from rough and crackly to smooth, and ulcerations may develop. Scabby sores or scaling of nasal tissue may also occur. Symptoms usually wax and wane, worsening during summer. Remissions can also occur.
Breeds Affected
Although all breeds can be affected, some breeds of dogs are at increased risk for developing discoid lupus. These include collies, Brittany spaniels, German shorthaired pointers, German shepherds, Shetland sheepdogs, and Siberian huskies.
Females are at slightly more risk than are males.
Risk Factors
Sunlight is thought to trigger discoid lupus and it's known to worsen symptoms.
Diagnosis
A biopsy is needed to confirm discoid lupus and to differentiate it from pemphigus, systemic lupus erythematosus, and a potentially dangerous form of lymphoma called mycosis fungoides, which has a poor prognosis.
Treatment
Sun avoidance or the use of sunscreens (ones especially made for canines; sunscreens for humans can be poisonous if licked off) containing zinc oxide can control the disease and often no further treatment is necessary. When treatment is needed vitamin E supplements are used for mild cases, whereas a combination of tetracycline and niacinamide may be effective in mild to moderate cases.
Topical steroids and 0.1% tacrolimus cream may also be used on the nose to reduce inflammation and promote healing of the sores. In severe cases, topical corticosteroids such as prednisone or immunosuppressants such as azathioprine may be needed.