Discoid Lupus Erythematosus (DLE)
also known as Lupus, Cutaneous Lupus Erythematosus, Nasal Solar Dermatitis and Collie Nose
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Discoid Lupus Erythematosus (DLE) is a chronic autoimmune cutaneous (skin) disorder primarily affecting the nose and is often triggered or worsened by solar exposure. It is most common in Collies (hence the popular term 'Collie Nose') and related breeds such as Australian Shepherds, Border Collies and Shetland Sheepdogs. It is a different condition to Vesicular Cutaneous Lupus Erythematosis (VCLE) which causes skin lesions in the armpits, abdomen and groin, and Systemic Lupus Erythematosus (SLE) which can affect multiple organ systems including joints, kidneys, skin and blood cells.
Being an autoimmune condition, it manifests by the immune system attacking the body's own skin cells leading to inflammation and skin damage as the surface of the skin begins to slough (shed) . The most commonly affected area is the nose however it can also affect eyelids, lips, mouth, ear flaps and rarely the feet or genitalia. It is a relatively rare disease overall but is considered to have a high hereditary component and occurs much more frequently in particular lines. Unfortunately, there is no DNA test yet available to identify the genetic markers and avoid the condition, so management within breeding programs is limited to discontinuing a line after the condition has presented - making it important for buyers to inform their breeders at all times when lupus is diagnosed. There is also a likelihood that the condition is underdiagnosed as many owners don't recognise symptoms and/or apply topical treatments or sunscreen to 'sunburnt' noses rather than investigate and obtain an official diagnosis and treatment. |
Loss of pigment, erythema (redness), crusting and ulceration - common symptoms of DLE or 'Collie Nose'
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The symptoms of DLE can include one or more of the following:
- Loss of pigment or discolouration on the nose leather/nasal planum (bridge of the nose)
- Change in texture and shape of nose from normal 'pebbly' texture to smooth, shiny surface
- Erosion changing the structural shape of the nose
- Skin redness (erythema)
- Skin scaling, flaking or crusting, including along the areas of the face where the skin meets the hair such as lips and eyelids
- Skin ulcerations or blistering
- Hair loss/alopecia
- Scarring
- Pain at affected areas
- Itching and/or scratching may or may not be present
Crusting on the nose, nasal planum and around the eyelids showing how the symptoms are particularly apparent where the hair meets the hairless areas of the face. Pigment loss noticeable.
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Symptoms showing loss of pigment on nose, scaling close to the hairline, a smoother, shinier skin texture and starting to show signs of erosion around nostrils changing the overall shape of the nose.
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DLE is a treatable condition and whilst incurable requiring lifelong treatment can be managed relatively easily throughout the dog's life once a plan and consistent monitoring is in place. If untreated however, it can cause the dog a great deal of pain, heavy bleeding if lesions develop near a major blood vessel, and the dog is at much higher risk of squamous cell carcinomas. It can also develop into SLE (although uncommon) which is much more difficult to treat and may not respond to treatment.
Whilst as previously mentioned DLE is thought to have a strong genetic component, and the underlying cause has not yet been identified, the most widely accepted cause and trigger of DLE is exposure to UV light radiation from the sun. UV light appears to worsen the condition and it is more common in sunny climates (like Australia). It is important to keep dogs with less pigment out of the sun as much as possible, and imperative that dogs diagnosed with DLE are protected from UV during intense sunlight hours. Sunscreen will not provide enough protection.
A diagnosis of DLE requires a biopsy to be performed by your veterinarian - there is no other way to confirm or rule out a diagnosis of this condition, and there are other conditions that can present with the same or similar symptoms. The biopsy will be performed under sedation or general anaesthetic as the nose is highly sensitive, and they may require stitches.
Treatment usually consists of topical and/or oral steroids such as prednisone to get the inflammation under control quickly. There can be undesirable side effects with long-term use of steroids so it is likely that once the skin is healed and the inflammation controlled, the dosages will decrease to the lowest effective maintenance dose in conjunction with other treatments. Other treatment options can include tetracycline/doxycycline antibiotics in combination with niacinamide (a B12 vitamin supplement), the combination of which has been found effective in a large number of dogs. There are also some oral and topical immunomodulators which have been shown to be effective in treating DLE, such as 0.1% tacrolimus ointment. The most important thing to remember in managing DLE (which will continue for the lifetime of the dog) is to avoid strong sunlight.
Whilst as previously mentioned DLE is thought to have a strong genetic component, and the underlying cause has not yet been identified, the most widely accepted cause and trigger of DLE is exposure to UV light radiation from the sun. UV light appears to worsen the condition and it is more common in sunny climates (like Australia). It is important to keep dogs with less pigment out of the sun as much as possible, and imperative that dogs diagnosed with DLE are protected from UV during intense sunlight hours. Sunscreen will not provide enough protection.
A diagnosis of DLE requires a biopsy to be performed by your veterinarian - there is no other way to confirm or rule out a diagnosis of this condition, and there are other conditions that can present with the same or similar symptoms. The biopsy will be performed under sedation or general anaesthetic as the nose is highly sensitive, and they may require stitches.
Treatment usually consists of topical and/or oral steroids such as prednisone to get the inflammation under control quickly. There can be undesirable side effects with long-term use of steroids so it is likely that once the skin is healed and the inflammation controlled, the dosages will decrease to the lowest effective maintenance dose in conjunction with other treatments. Other treatment options can include tetracycline/doxycycline antibiotics in combination with niacinamide (a B12 vitamin supplement), the combination of which has been found effective in a large number of dogs. There are also some oral and topical immunomodulators which have been shown to be effective in treating DLE, such as 0.1% tacrolimus ointment. The most important thing to remember in managing DLE (which will continue for the lifetime of the dog) is to avoid strong sunlight.
Early DLE symptoms showing pigment loss, blistering and the beginning of flaking along the hairline of the nasal planum.
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The same dog showing the rarer but known potential impact of DLE on the distal extremities.
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