In this episode of Your Vet Wants You to Know, Dr. Brittany Lancelotti, a board-certified veterinary dermatologist, discusses discoid lupus erythematosus (DLE) in dogs with fellow veterinary dermatologist Dr. Alicia Webb-Milum. They explore the symptoms, causes, and diagnosis of DLE, using a case study of Jack, a German Shepherd suffering from the disease. They also cover the steps to diagnose DLE, including cytology and biopsy, and discuss effective treatment plans and the importance of sun protection.
Table of Contents
Welcome Back, Dr. Alicia Webb Milum
[00:01:04] Dr. Lancellotti: Welcome, everyone, to today’s episode of Your Vet Wants You To Know. Today, we’re gonna be talking about another autoimmune disease called discoid lupus erythematosus (DLE). It’s much easier to say DLE than discoid lupus erythematosus every single time. And I’m joined again by one of my very dear friends, and a veterinary dermatologist out in Oklahoma City, Dr. Alicia Webb-Milum. Welcome, Dr. Webb-Milum.
[00:01:31] Dr. Webb-Milum: Thank you so much for having me back. I’m always happy to be here.
[00:01:35] Dr. Lancellotti: Tell us a little bit about your background and your journey through veterinary medicine.
[00:01:40] Dr. Webb-Milum: I am a board certified veterinary dermatologist in Oklahoma City, but I started my career in primary practice. As a family practice veterinarian, I quickly fell in love with skin disease and wanted to know more, so I did my dermatology residency with the animal dermatology group in Tustin, California, which is where I met Dr. Lancellotti, and we’ve been friends ever since.
[00:02:02] Dr. Lancellotti: And we’ve been each other’s dance buddies, on the dance floor, every time we have our dermatology conference.
[00:02:07] Dr. Webb-Milum: Watch out. We’ve got some moves.
Jack, a sweet German Shepherd with Discoid Lupus Erythematosus (DLE)
[00:02:11] Dr. Lancellotti: Today, Dr. Webb-Milum and I are going to be talking about DLE, which is an autoimmune disease that affects primarily the nose of dogs. I want to tell you a little bit about one of my favorite patients, Jack. He is one of the sweetest German Shepherds that I’ve ever met. And his equally sweet owner, Dorothy, is just an amazing person. If you know anything about me and how I like to practice, you’ll know that I joke about bribing the receptionist to put all of the Golden Retrievers on my schedule. I just adore them so much. As much joy as I have seen Goldens on my schedule, I have equally as much angst about seeing new German Shepherds. I hate to be breedist, but they’re one of the few breeds that has tried to lunge with minimal warning. They’ll also hide quite a bit. Or if I’m really lucky, they’ll be big softies. So I would say that German Shepherds have been some of my best and my most challenging patients over the years, both in behavior and in skin disease. Jack’s behavior, fortunately, has always been very heartwarming and very charming. He is a perfect gentleman every time he comes in to see me. But his poor nose has been quite the challenge. Jack has a condition called discoid lupus erythematosus, or DLE for short. Jack’s nose, over the course of several months, started to lose some color to it. It became really crusty and raw, and then started bleeding all over poor Dorothy’s home. She came to see me so that I could help her figure out what was going on with Jack’s nose. Dr. Webb-Milum, have you had cases like this, where the owner’s just not quite sure what’s happening with their dog’s nose?
[00:03:54] Dr. Webb-Milum: So many cases! And you’re right, it’s typically DLE, but there can be other causes, as well.
Introduction to Discoid Lupus Erythematosus (DLE)
[00:03:59] Dr. Lancellotti: Let’s talk a little bit about DLE. This is an autoimmune disease, and in autoimmune diseases, the immune system (which is there to help fight off things that can harm your body like infections or cancer) is actually fighting normal parts of the body. And in this case, the part of the body that’s being affected is typically the nose. Sometimes, the immune system can also attack the eyelids, or other areas where the skin meets the mucous membranes (like around the mouth or the perivulvar skin, the skin around the anus or the anogenital regions- which is a fancy word for where their pee and poop come out).
Causes of Discoid Lupus Erythematosus (DLE)
Dr. Lancellotti: In certain autoimmune diseases, there can be a trigger- something that stimulates the immune system to be overreactive. There are certain autoimmune diseases that can be triggered by bug bites, certain medications, vaccines, and even cancers can trigger autoimmune diseases. Sometimes, we don’t know what the trigger is, and the autoimmune disease starts for no apparent reason. We call that ‘idiopathic.’ What is the most common trigger for DLE?
[00:05:06] Dr. Webb-Milum: Sun exposure can be a major trigger for a lot of dogs with DLE, which is why we see so much of it in Southern California.
[00:05:14] Dr. Lancellotti: Yeah. Essentially, this is like having a really severe reaction to a sunburn. And poor Jack lives in a place called Bakersfield, California. During the warmer months of the year, it can bake up in Bakersfield, so his nose was just getting cooked, and his immune system was really out of control because of how much sunlight he was being exposed to.
[00:05:37] Dr. Webb-Milum: That’s certainly a factor, but lupus is really multifactorial, in that there seems to be a lot of things that play a role in this disease, specifically. As you mentioned, we really see this, most commonly, in German Shepherds, but we certainly see it in other breeds as well.
How does a dog's nose look with discoid lupus erythematosus?
[00:05:50] Dr. Lancellotti: When we have an animal that comes in, with this particular disease, we want to make sure that we are treating the right thing, so we need to get a diagnosis first. Oftentimes, owners will bring the animal in because they’ve lost some pigment or coloring. The nose is no longer that nice black color that it typically is. It can turn pink or gray, and they lose a lot of the cobblestone architecture to their nose. Instead of it having those really tiny little nice patterning to the top and the front of the nose, it becomes smooth, and sometimes can be really ulcerated.
How is discoid lupus erythematosus diagnosed?
Dr. Lancellotti: So if we have a patient who comes in with some changes that make us suspicious for DLE, what’s your first approach, in terms of getting some diagnostics or some testing that you want to do?
[00:06:39] Dr. Webb-Milum: Well, the first answer is always cytology. I always want to make sure if I am dealing with an infection or not. And if so, what is the underlying reason for that? So cytology is always the best start, but for most diseases, to get a definitive answer, we’re usually reaching for a biopsy.
[00:06:56] Dr. Lancellotti: Yep, absolutely. I think biopsy is one of the most helpful tools. And the best time to do this is after we’ve made sure that we’ve cleared up any secondary infection that the animal might have, so that cytology is very helpful in looking to see if there are bacteria present. If there’s a lot of bacteria, that can get in the way of the pathologist being able to see the primary disease process. Usually, the bacteria are secondary to some primary disease. So we’ll clear up the bacteria and then perform a biopsy.
Biopsy of the Nose for Discoid Lupus Erythematosus
Dr. Lancellotti: For a biopsy, what we’re first going to do is give your pets some medicine to sedate or anesthetize them. Sometimes, they just need a little bit to make them sleepy and not really aware of what’s going on. Other times, we’re going to want them fully under anesthesia, which will depend on your individual animal and what your veterinarian’s recommendations are. When we do this biopsy, we have to keep in mind that the nose has a lot of nerve endings and blood vessels, so we really want to make sure that they don’t feel what we’re doing, and that they hold still, so that we can move quickly and minimize bleeding. Once the animal is sleeping, we’re going to inject a small amount of lidocaine (local anesthetic) to numb the area. There are some other different types of local anesthetics, but this is something to make it so that they don’t feel what’s happening, specifically on their nose. Then, we’re going to use a circular scalpel (which is about the size of a pencil eraser) called a punch biopsy to take a few samples of skin on the nose. They may even be smaller, depending on how big your pet’s nose is. Obviously, we don’t want to take the entire nose off. We’re just taking little samples. Then, after the piece of skin has been removed, we’re going to place some sutures to close the biopsy site so that it doesn’t bleed. It may ooze a little bit afterwards, just because there are lots and lots of blood vessels there. Typically, your animal is going to wear a cone or an e collar for about two weeks afterwards, because the last thing that we want is them scratching their nose while their biopsy site is healing. So we want to keep that nice and closed, so that they don’t create a crime scene, on your house, by scratching out those sutures.
[00:09:03] Dr. Webb-Milum: Yeah. These can be really bloody. Another thing to mention is that it can be challenging to biopsy a nose, especially if you have a small dog. Afterwards, they can look a little different, but they typically heal nicely, once the body has had a chance to do remodeling.
Can Discoid Lupus Erythematosus be Treated?
[00:09:17] Dr. Lancellotti: Yeah. I’ve got some great pictures, on the website, from before and after some of the patients that I’ve treated with DLE, over the years. And even some of the ones that come to me with really chronic changes to their nose, once we get a diagnosis, and we get them on the right treatment, their noses can go back to close to pretty normal, if we find the right plan, in terms of getting their immune system under control. Once we’ve submitted that biopsy and the pathologist gives us a diagnosis of DLE, what sort of medications can we reach for?
[00:09:50] Dr. Webb-Milum: It really depends on the patient and the severity. The standard treatment that we’re typically reaching for is prednisone or another type of steroid, but these can certainly have side effects, both in the short term and long term, which can be really unsavory. Depending on the severity, we might add other drugs, which can range from mycophenolate or oclacitinib (the drug name for Apoquel) at higher doses, other immunosuppressive medications like cyclosporine. If your dog is not super painful, we may reach for a topical immunosuppressive drug like tacrolimus or topical steroids, but your pet has to be comfortable enough to allow topical treatments to start.
[00:10:32] Dr. Lancellotti: Yeah, that’s one of the challenges with this disease. Topical treatment can be a little bit tough if they’re painful. It can also be a little bit tough because some of the topicals that we put on the nose may be very easily licked off. It can be tough to get them to not lick when they’ve got something right on the top of their nose, especially if you’ve trained your dog to lick peanut butter off their nose, earlier on in their lifetime. But just like with any other autoimmune disease that we treat in dermatology, every animal’s going to have a different treatment plan, because no two animals will respond exactly the same to the exact same protocol.
So there are a number of different medications that can be used for treatment of DLE, depending on the severity of the disease, your pet’s underlying health, and what’s going on with the rest of their body, taking into consideration how those medications may affect other organ systems (liver, kidneys, heart), and what your veterinarian is comfortable with. We all have different experience with different types of medications, so many times, I’m going to be reaching for medications that I feel very comfortable using, because I have a lot of clinical experience with them. If those don’t work, I’ll transition to things that maybe I don’t have as much experience with, but would also be appropriate to use, in this situation. So it’s really important to have a working relationship with a veterinarian that you trust and someone who feels comfortable with treating this particular disease.
Dogs with Discoid Lupus Erythematosus Should Avoid Sun
Dr. Lancellotti: Management is also really important. We talked about how UV exposure can be something that can trigger this particular disease. What are some of the things that we can do to prevent DLE from worsening?
[00:12:14] Dr. Webb-Milum: We want to make sure that we are minimizing the pets’ exposure to damaging UV rays, especially when the rays are the strongest- between 9 AM and 5 PM. This can change, depending on where you are, the dog’s lifestyle, or whether they have access to a doggie door. This can be challenging, but typically, the sunnier it is, the worse it is for DLE.
[00:12:35] Dr. Lancellotti: Yeah, I absolutely agree. It’s really tough here in Southern California to get these dogs completely in remission, especially during the summertime. And I will have conversations with owners about not changing the medications too much during those really sunny months of the year, and waiting until we move into fall, when the sun’s rays are going to be less strong, before we pull back on some of our medications while the animal’s in remission. So one of the first things that Dorothy started doing, once we knew what was happening, was to make Jack an indoor dog.
Those sun’s rays are often strongest between 9 AM and 5 PM, but this changes with the season and where you are in the world. Basically, the sunnier it is, the worse it is for DLE. So if the dog is outside during daytime hours, it’s really best to limit how long they’re outside. Sunbathing is a big no-no in these dogs. There’s a lot of blood vessels, in a dog’s nose, that can start bleeding, and sometimes, even spraying blood, if this disease gets really bad. If the dog knocks its nose on something and damages that fragile tissue, it’s going to be really tough to control that bleeding. So preventing worsening of the disease by limiting their exposure to the sun, for me in Southern California, is cornerstone to recovery and control.
Tools for Dogs to Avoid Sunburn on the Nose
Dr. Lancellotti: There are a couple of tools that I will recommend to my owners, in addition to just avoiding sun exposure. One is going to be sunscreen. Do you have a particular sunscreen that you usually recommend or reach for?
[00:14:01] Dr. Webb-Milum: This is tough because the most effective sunscreens, in my experience and opinion, are zinc-based. And while they are very effective in larger doses, they can also be toxic to dogs. So that’s definitely a conversation we need to have with the owner- using it in small doses and using it appropriately. The other thing is that they must be reapplied, like in people.
[00:14:21] Dr. Lancellotti: Yeah, so this is a situation where you should ask your veterinarian which sunscreen they like, and which one they feel comfortable recommending. These may change, and you’d ideally like something with some research to back up any claims of sun protection, effectiveness and safety in dogs, because it is definitely in an area where the dog can lick that off and ingest it.
There is a product that was specifically designed by a pet owner whose dog had DLE called the Dog Nose Protector. Have you heard of this?
[00:14:50] Dr. Webb-Milum: I have. I’ve had a few patients tolerate it. How about you?
[00:14:54] Dr. Lancellotti: Well… I have recommended it to several patients. The reason I really like this is because it was actually evaluated in a research study. What they found was that this fitted canvas nose cover, which clips behind the dog’s head to stay on the nose, blocked almost 100 percent of UV exposure. So if you can work on creating a positive association to this nose cover, by using some high value rewards when the animal wears it, and if the animal keeps it on, it can be a really great tool and prevent having to use sunscreen. What I’ve found is that a lot of the patients, where the owner has purchased it and tried to put it on, have just had a really hard time being comfortable with it.
So for those of you who are out there listening, if your pet has worn the Dog Nose Protector and you’ve got pictures or videos, and they’re happy having that on their face, I would love to see those. Go ahead and send those to us, so that we can see these pictures and share them with the audience. If you’ve got tips or tricks for how to train your animal to get this on their nose, I’d love to hear that, as well.
In that same study that looked at the Dog Nose Protector, they also evaluated something called the Out Fox Field Guard. This head covering was originally designed to protect against fox tails or grass awns, from going up the nose and in the ears, when animals are out hiking. And we have a ton of fox tails here in Southern California, so I do recommend this on a regular basis, because I pull fox tails out of ears all of the time.
That study that looked at the UV exposure, using the Dog Nose Protector, also evaluated the Outfox Field Guard, and this actually blocked about 75 percent of UV rays, as well. It’s not 100 percent effective, the way the Dog Nose Protector is, but this is a lot better tolerated, in terms of it just being this mesh covering that goes over the dog’s entire head, rather than something that goes just on the nose.
[00:16:55] Dr. Webb-Milum: Yeah, and it’s really important that we find something that’s tolerated by the dog. When I am treating a patient, I want to make sure that they’re still living the life that they want, so however we can make these things more tolerated by the pet is always very important to me.
Remission and Management of Discoid Lupus Erythematosus
[00:17:09] Dr. Lancellotti: Yeah, absolutely. Basically, anytime we’re treating an autoimmune disease, we have two stages of treatment. We have the first stage where we’re trying to induce remission (getting the disease under control). We want that nose to go back to looking as normal as possible. There may be some scarring if there was really severe damage or really chronic changes that were there, but we want the immune system to stop attacking the nose, the eyelids, or anywhere else that it was causing problems.
Once the animal is in remission, our second stage of treatment is going to be to find the lowest effective dose of the safest effective medications for longterm management. The immune system has a really long memory, and if we pull back on our medications or stop them all together, there’s a good chance that the immune system can remember what it was attacking before, and the disease comes out of remission. So make sure to schedule those recommended rechecks and follow up exams with your family veterinarian, or with a veterinary dermatologist that you’re working with, so that you can be able to come up with a plan to induce remission and establish a maintenance plan for those medications.
[00:18:20] Dr. Webb-Milum: And also be aware that this disease can wax and wane. It can get better and it can get worse, especially seasonally, so it’s really important to go with the flow, doing the best to manage the disease and keep the dog comfortable, knowing that it’s not a ‘set it and forget it’ type disease. We want to keep your dog comfortable in that moment, in that season, and that might change over time.
What to Know About Discoid Lupus Erythematosus (DLE)
[00:18:43] Dr. Lancellotti: Do you have any big takeaways that you want to share, with our owners, about management or diagnosis and treatment of DLE?
[00:18:52] Dr. Webb-Milum: Sure. So DLE is a disease in which the immune system is attacking the deepest cell layer of the nose, and that can result from loss of pigment to change in the nasal architecture to pretty significant erosions on these noses. They can be painful, and these can be quite severe in certain cases, especially if we don’t limit things like UV light. However, it’s really important that this is diagnosed because there can be other conditions that mimic this, especially some cancerous conditions called squamous cell carcinoma. So we want to make sure that we know what we’re treating and then work closely with your veterinarian to find the best plan for your dog, which might change over time.
[00:19:33] Dr. Lancellotti: That’s all great advice. Getting the diagnosis is super important. You mentioned cancerous conditions. There are other autoimmune conditions, infectious diseases, and lots of different things that can look like DLE, so having a diagnosis is critical to being able to treat the problem appropriately. If your pet has some type of nasal disease, and you’re curious about this, I would highly recommend looking to see if there is a veterinary dermatologist in your area, as that extra level of specialist care is sometimes needed in these more complicated cases. You can join our Facebook group and share stories or pictures about your pet with DLE, and especially, if your animal wears the Dog Nose Protector. We would love to see that.
Scratching the Itch: Food on Foot
Dr. Lancellotti: We like to end each episode a segment called Scratching the Itch. This is a segment that is designed to highlight something, whether it’s a product, a human interest story, or a website that provides relief or just makes you feel good. Hence, scratching the itch.
Today’s ‘scratching the itch’ is an organization here in Los Angeles called Food on Foot, which is a nonprofit dedicated to assisting our unhoused and low income neighbors, in Los Angeles, with nutritious meals, clothing, and a fresh start through life-skills training, full time employment, and permanent housing. Every Sunday, they offer fresh meals, fresh produce, as well as clothing to our neighbors in Los Angeles.
What I love about Food on Foot is that they also provide a jobs and housing program, to help people to earn their way off the streets with a full time job, a fully furnished apartment, a life-skills education, and a really big boost in confidence. You can see the difference in these people, as they go through these programs.
The other thing I really like about Food on Foot is that everybody can get involved. I was initially looking for an organization to get involved, with my daughter, Maya, so that we could give back to the community and get involved with helping our neighbors. And a lot of the organizations that we looked at had restrictions on the ages that could be involved, but Food on Foot allows kids, as young as 6 years of age, to come and help with their Sunday food service. For me, this was such a great way to get Maya involved in community outreach and service, so if you are looking for an organization in Southern California to get involved with, this is a great group that has done a lot for the community.
But there are a lot of organizations, just like Food on Foot, all throughout the country, so if you’re looking for a way to get involved in your community, certainly don’t hesitate to see what’s out there and help out in any way that you can. Organizations like this really need volunteers, on a regular basis, in order to survive and continue to provide those crucial resources that people need.
[00:22:33] Dr. Webb-Milum: That is wonderful. I’m glad that you and Maya are involved in this organization.
[00:22:37] Dr. Lancellotti: Yeah, she loves it. And she’s asking me all the time, “When can we go back to Food on Foot? Do they have anything available this weekend?” Honestly, I’m pretty impressed. A lot of times, we go to volunteer and they’re full for their volunteer schedule, so we have to make an effort to look see, ahead of time, what weekends are available. They’ve got so many people that really want to help out with their mission. They’ve got a great setup, every Sunday.
[00:23:01] Dr. Webb-Milum: Wonderful.
[00:23:04] Dr. Lancellotti: Thank you so much for coming on and talking about DLE. I really appreciate that. I think this is going to be really helpful for owners who are dealing with this disease and struggling to understand what’s happening with their pet.
[00:23:15] Dr. Webb-Milum: Thank you for having me, and thank you for creating this resource, both for veterinarians and for pet owners. I think it’s tremendously helpful.
[00:23:22] Dr. Lancellotti: I appreciate that. And to everyone listening, I look forward to your next visit with Your Vet Wants You to Know.
References:
- Banovic, Frane, et al. “Clinical and Microscopic Features of Generalized Discoid Lupus Erythematosus in Dogs (10 Cases).” VETERINARY DERMATOLOGY, vol. 27, no. 6, Dec. 2016, p. 488–+.
- Banovic, Frane, et al. “Ciclosporin Therapy for Canine Generalized Discoid Lupus Erythematosus Refractory to Doxycycline and Niacinamide.” Veterinary Dermatology, vol. 25, no. 5, Oct. 2014, p. 483.
- Milich, Kelsey A., et al. “Comparison of Three Canine Nose Guards for Reduction of Ultraviolet (UVA and UVB) Solar Radiation.” Veterinary Dermatology, vol. 34, no. 1, Feb. 2023, pp. 64–69.
- Rossi, Michael A., et al. “Generalized Canine Discoid Lupus Erythematosus Responsive to Tetracycline and Niacinamide Therapy.” Journal of the American Animal Hospital Association, vol. 51, no. 3, May 2015, pp. 171–75.
