Discoid lupus erythematosus, also known as DLE, is a rare autoimmune disease, affecting the basal cell layers of the skin. It may occur in cats, but mostly affects dogs. Some humans suffer from this condition, the most popular being the singer Seal with distinctive scars on his cheeks due to an infection as a child. Common dog breeds affected by this condition include German Shepherds, Siberian Husky, Brittany Spaniel, Collie, Shetland Sheepdog and German Short-haired Pointer. This condition is more common during summer seasons due to increased sun exposure.

Differential diagnosis through biopsy is needed to distinguish DLE from pemphigus, ringworm, solar dermatitis and other types of dermatitis.

Corticosteroid therapy, oral omega-3, omega-6 fatty acids and vitamin E are used for treatment. To prevent the disease from occurring, sunscreens or avoiding extreme sun exposure is important. Severe cases may need oral tetracycline, azathioprine, niacinamide or chlorambucil. These medications are administered throughout the canine’s life upon onset of the disease.

The first symptom of DLE is loss of pigment and scaling of the nose, which is found in 90% of dogs with this condition. The nose surface becomes ulcerated, smooth and gray. Over time, the genitals, ears, lips and skin around the eyes may also develop lesions. These lesions could progress to ulceration and tissue destruction.

Sun exposure is a contributing factor to Discoid lupus erythematosus.