Sunlight Can Make Skin Disease Worse
October 23, 2012
Discoid lupus erythematosus (DLE) is an autoimmune disease wherein a dog becomes allergic to its own tissues. This disease results in crusting, depigmentation, redness, and ulceration of the nose. Lesions may also appear around the eyes, ears, limbs, and other areas. DLE can occur at any age, and is seen more often in such breeds as Collies, German Shepherds, Shelties, and Siberian Huskies.
Fortunately, the prognosis for this disease is usually good, although treatment must usually be continued for life. DLE can get better or worse on its own, such that there may be times when no treatment is necessary. In some chronic cases, DLE can develop into a malignant type of cancer called squamous cell carcinoma, although this happens rarely.
Exposure to U-V light (e.g. sunlight) can exacerbate or even precipitate this condition. This is why it tends to be more severe in summer or in sunny climates. Depigmentation of the nose will also make your dog more susceptible to sunburns.
Treatment and correction of DLE involves two steps. First, an accurate diagnosis must be made, since nasal depigmentation and/or ulceration can have many causes. This can be done via blood tests and skin biopsies. Because the nose is a very sensitive and vascular area, a general anaesthetic is required to take a proper biopsy.
Secondly, once a diagnosis of DLE has been made, treatment involves avoiding intense sunlight, various topical and systemic medications and, in extreme cases, surgical correction. In some cases, applying a sunscreen to the depigmented areas may prove helpful. Keeping the patient indoors during the day (between 8 a.m. and 5 p.m.) and allowing generous access outdoors at night instead can also minimize clinical signs.
Topically, creams or ointments containing Vitamin E or steroids may also prove helpful. Oral Vitamin E (about 400-800 I.U. twice daily) has proven to be beneficial as well. Severe cases respond to corticosteroid therapy.
Finally, recent reports have described good success in using reconstructive surgery to correct the nasal area. The depigmented, ulcerated areas are excised and replaced (by means of a surgical skin graft) with normal skin. Your veterinarian can suggest which treatment options are most effective.