Discoid Lupus Erythematosus in Dogs

Being one of the most common autoimmune skin disorder in dogs in the United States, DLE was diagnosed in large numbers in the 70’s and 80’s. However, today there are many fewer cases of true lupus that are diagnosed. DLE can mimic other skin disorders and this does make it somewhat difficult to differentiate. 

Some of the disorders that it may look like are mucocutaneous pyoderma (dermatitis that presents due to use of antibiotics), pemphigus complex, cutaneous drug reaction, erythema multiforme, cutaneous lymphoma, uveodermatologic syndrome, solar dermatitis (collie nose), systemic fungal infections, tick borne diseases, cancer, kidney disease, heart disease, and viral infection, amongst others. 

Most of the time your dog will not present with any pain or discomfort, rather you will notice changes around his nose in regards to color, texture, scabs etc. Your dog will present with irritation and possible hair loss around his nose among other symptoms. These symptoms will be discussed below in depth.

Discoid lupus erythematosus (DLE) is a common autoimmune skin condition in dogs. Symptoms will be mostly in his nasal area but can also impact other areas of his face and head. It is relatively easy to diagnose and is also treatable.

Symptoms are generalized and can mimic other skin conditions. Some of the symptoms are listed below. 

• Depigmentation – Your dog’s nose may begin to lose its color as well as his lips
• Scaling – You may notice your dog’s nose begin to develop a “crust” on it as well as his skin developing dandruff
• Erythema – His skin may begin to redden in patches around his limbs, mouth, and ears 
• Erosions – Ulcers may begin to develop on his nose and other areas of his head and limbs; these ulcers can appear on or in his ears, mouth, tongue and genitalia 
• Alopecia – He may begin to lose his hair around his nose and other areas of his face and body without other explanation 
• Your dog’s nose may lose its bumpiness and appear flat and turn a gray color
• Initial photo dermatitis – your dog may have had a reaction to sunlight that resulted in ongoing problems such as DLE
• Aggravated by sunlight exposure – When he is out in the sunlight without protection his symptoms may flare up

Types

There are certain breeds of dogs that have been identified as having a higher possible risk of developing DLE

• Collies
• Shelties
• German Shepherds
• Siberian Huskies
• Brittany Spaniels

There is, unfortunately, no known cause for DLE and it is thought to be a hereditary condition. It has been seen in some cases that your dog most likely had an allergic reaction to sunlight and then began to develop DLE symptoms after that. If your dog is young to middle aged, he may also be at a higher risk of developing DLE.

Diagnosing discoid lupus erythematosus in dogs can sometimes be difficult due to how many other disorders can be very similar in their symptoms. Your veterinarian will want to know about any changes to your dog’s environment or eating habits to determine if it is possible he is having an allergic reaction to something. Your doctor will also want to know what things you have noticed that have you concerned, such as change in his nose color or ulcers.

Your veterinarian will want to take a biopsy of your pet’s skin to better help with diagnosis as well as blood work to eliminate other possible causes of his symptoms. Formal diagnosis of DLE will be done via a physical exam, a detailed history of your dog’s medical care, biopsy results, and how he reacts to trial treatments.

Treatment will be to help your dog’s symptoms rather than curing his DLE as there is no cure. It is important to note that this is considered a cosmetic condition and most likely is not causing your dog any pain or discomfort. Treatment will be done in conjunction with other treatment options as discussed below.

Due to mucocutaneous pyoderma not being different in symptoms from DLE your dog may be treated with Cephalexin 10-15mg daily for 30 days primarily. Once this treatment is complete your veterinarian will move on to the next steps. 

Following treatment for possible mucocutaneous pyoderma, avoiding excessive sun exposure for your dog will be important. It will also be important to begin using sunscreen on him and providing him with vitamin E and omega 3 fatty acids. 

Lastly, there are the medications tetracycline and niacinamide which can be used together to help manage symptoms of DLE. This medication protocol does have side effects of possible vomiting, diarrhea and anorexia. Both of these medications can be trialed for up to 60 days and if there is no change in symptoms, they will be discontinued and an anti-inflammatory will replace them. 

Topical steroids can be used when the area of your dog’s body that is impacted is small enough. However, it is important to be aware that too strong of a steroid can cause scarring. The primary steroid cream is tacrolimus topical .1%, this steroid has been shown in at least one study to be enough to treat a dog’s DLE symptoms alone and all other medications could be stopped. Your dog will be slowly weaned down off the steroid medications as well.

Treatment is lifelong and centers around sun protection first and foremost with continued monitoring for symptoms. Due to there being no known cause of DLE there is also no cure and therefore lifelong management will be necessary. Your veterinarian will suggest when to bring your dog back in and how to administer any medications prescribed.

Your dog’s symptoms can disappear within a few days to months and with your veterinarian, an appropriate course of treatment will be determined. Recovery will be based on your dog’s quality of life and symptoms abating.