Title: Canine discoid lupus erythematosus

{{Short description|Autoimmune disease}}
{{About|discoid lupus erythematosus in dogs|the disease in humans|lupus erythematosus}}

'''Discoid lupus erythematosus (DLE)''' is an uncommon [[autoimmune disease]] of the [[Stratum germinativum|basal cell layer]] of the [[skin]].  It occurs in humans&lt;ref&gt;[http://www.aocd.org/skin/dermatologic_diseases/discoid_lupus_eryt.html  American Osteopathic College of Dermatology, &quot;Discoid Lupus Erythematosus&quot;].&lt;/ref&gt; and cats, more frequently occurring in [[dog]]s. It was first described in dogs by Griffin and colleagues in 1979.&lt;ref&gt;{{Cite journal|last1=Griffin|first1=C.E.|last2=Stannard|first2=A.A.|last3=Ihrke|first3=P.J.|last4=Ardans|first4=A.A.|last5=Cello|first5=R.M.|last6=Bjorling|first6=D.R.|date=November 1979|title=Canine discoid lupus erythematosus|journal=Veterinary Immunology and Immunopathology|language=en|volume=1|issue=1|pages=79–87|doi=10.1016/0165-2427(79)90009-6|pmid=15612271}}&lt;/ref&gt;&lt;ref&gt;{{Cite journal|last1=Olivry|first1=Thierry|last2=Linder|first2=Keith E.|last3=Banovic|first3=Frane|date=December 2018|title=Cutaneous lupus erythematosus in dogs: a comprehensive review|journal=BMC Veterinary Research|language=en|volume=14|issue=1|pages=132|doi=10.1186/s12917-018-1446-8|issn=1746-6148|pmc=5907183|pmid=29669547 |doi-access=free }}&lt;/ref&gt; DLE is one form of cutaneous lupus erythematosus (CLE). DLE occurs in dogs in two forms: a classical facial predominant form or generalized with other areas of the body affected. Other non-discoid variants of CLE include vesicular CLE, exfoliative CLE and mucocutaneous CLE.&lt;ref&gt;{{Cite journal|last=Banovic|first=Frane|date=January 2019|title=Canine Cutaneous Lupus Erythematosus|journal=Veterinary Clinics of North America: Small Animal Practice|language=en|volume=49|issue=1|pages=37–45|doi=10.1016/j.cvsm.2018.08.004|pmid=30227971|s2cid=52295619 }}&lt;/ref&gt; It does not progress to systemic [[lupus erythematosus]] (SLE) in dogs.  SLE can also have skin symptoms, but it appears that the two are either separate diseases.&lt;ref name=Ettinger_1995&gt;{{cite book|author1=Ettinger, Stephen J. |author2=Feldman, Edward C. |title=Textbook of Veterinary Internal Medicine|edition=4th|publisher=W.B. Saunders Company|year=1995|isbn=0-7216-6795-3|oclc=28723106}}&lt;/ref&gt;  DLE in dogs differs from SLE in humans in that [[plasma cell]]s predominate [[histology|histologically]] instead of [[T lymphocyte]]s.&lt;ref name=Griffin_2001&gt;{{cite book|last=Griffin|first=Craig E.|author2=Miller, William H. |author3=Scott, Danny W. |year=2001|title=Small Animal Dermatology|edition=6th|publisher=W.B. Saunders Company|isbn=0-7216-7618-9|oclc=43845516}}&lt;/ref&gt;  Because worsening of symptoms occurs with increased [[ultraviolet]] light exposure, sun exposure most likely plays a role in DLE, although certain breeds (see below) are predisposed.&lt;ref&gt;{{cite web | last = Mueller | first = Ralf S. | title = Immune-mediated skin diseases | work = Proceedings of the 50° Congresso Nazionale Multisala SCIVAC | year = 2005 | url = http://www.ivis.org/proceedings/scivac/2005/Mueller1_en.pdf?LA=1 | format = PDF | accessdate = 2007-03-13 }}&lt;/ref&gt;  After [[pemphigus|pemphigus foliaceus]], DLE is the second most common autoimmune skin disease in dogs.&lt;ref name=NAVC&gt;{{cite web | last = Osborn | first = S. | title = Autoimmune Diseases in the Dog | work = Proceedings of the North American Veterinary Conference | year = 2006 | url = http://www.ivis.org/proceedings/NAVC/2006/SAE/128.asp?LA=1 | accessdate = 2007-03-13 }}&lt;/ref&gt;

==Symptoms==
[[Image:Canine discoid lupus 3.jpg|thumb|Canine discoid lupus erythematosus showing loss of noseprint, depigmentation, ulceration and tissue destruction - all characteristic of the syndrome]]The most common initial symptom is scaling and loss of pigment on the nose. The surface of the nose becomes smooth gray, and ulcerated, instead of the normal black cobblestone texture.  Over time the lips, the skin around the eyes, the ears, and the genitals may become involved.&lt;ref&gt;{{cite journal |vauthors=Gerhauser I, Strothmann-Lüerssen A, Baumgärtner W |title=A case of interface perianal dermatitis in a dog: is this an unusual manifestation of lupus erythematosus? |journal=Vet Pathol |volume=43 |issue=5 |pages=761–4 |year=2006 |pmid=16966456 |doi=10.1354/vp.43-5-761|s2cid=25729680 |doi-access=free }}&lt;/ref&gt;  [[Lesion]]s may progress to [[Ulcer (dermatology)|ulceration]] and lead to tissue destruction.  DLE is often worse in summer due to increased sun exposure.

==Diagnosis==
DLE is easily confused with [[Photodermatitis|solar dermatitis]], [[pemphigus]], [[ringworm]], and other types of dermatitis.  [[Biopsy]] is required to make the distinction.  [[Histopathology|Histopathologically]], there is [[inflammation]] at the [[Stratum germinativum|dermoepidermal junction]] and degeneration of the basal cell layer.&lt;ref name=NAVC/&gt;  Unlike in SLE, an [[anti-nuclear antibody]] test is usually negative.&lt;ref name=Ettinger_1995/&gt;

==Treatment==
Avoiding sun exposure and the use of sunscreens (not containing [[zinc oxide]] as this is toxic to dogs&lt;ref name=&quot;kiriluk2019&quot;&gt;{{Cite news|url=https://www.dailyherald.com/submitted/20190717/protect-your-dog-from-the-extreme-heat-of-summer|title=Protect your dog from the extreme heat of summer|last=Kiriluk|first=Ellaine|date=2019-07-17|journal=[[Daily Herald (Arlington Heights, Illinois)|Daily Herald]]|location=[[Arlington Heights, Illinois]]|language=en-US|access-date=2020-04-18|quote=Human sunscreen is safe if it doesn't contain zinc oxide, which can be toxic if ingested. Since there are ingredients in sunscreens that can be toxic to both cats and dogs, [Dr. Ruth MacPete, DVM] recommends using only a veterinarian-approved sunscreen.|url-status=live|archive-url=https://web.archive.org/web/20190718170238/https://www.dailyherald.com/submitted/20190717/protect-your-dog-from-the-extreme-heat-of-summer|archive-date=18 July 2019}}&lt;/ref&gt;&lt;ref name=&quot;devera2019&quot;&gt;{{Cite news|first=Carina|last=Devera|url=https://www.marinij.com/2019/07/08/beware-the-hidden-toxins-that-seem-harmless-but-can-be-deadly/|title=Beware the hidden toxins that seem harmless but can be deadly|date=2019-07-08|journal=[[Marin Independent Journal]]|location=[[San Rafael, California]]|language=en-US|access-date=2020-04-18|url-status=live|archive-date=9 July 2019|archive-url=https://web.archive.org/web/20190709132500/https://www.marinij.com/2019/07/08/beware-the-hidden-toxins-that-seem-harmless-but-can-be-deadly/|quote=Zinc oxide is effective as a sunscreen for humans, but it’s toxic for dogs. If ingested, it can damage your dog’s red blood cells.}}&lt;/ref&gt;) is important.  Topical therapy includes [[corticosteroid]] and [[tacrolimus]]&lt;ref&gt;{{Cite journal|last1=Griffies|first1=J. D.|last2=Mendelsohn|first2=C. L.|last3=Rosenkrantz|first3=W. S.|last4=Muse|first4=R.|last5=Boord|first5=M. J.|last6=Griffin|first6=C. E.|date=August 2002|title=Topical 0.1% tacrolimus for the treatment of discoid lupus erythematosus and pemphigus erythematosus in dogs|journal=Veterinary Dermatology|language=en|volume=13|issue=4|pages=211–229|doi=10.1046/j.1365-3164.2002.00298_3.x|issn=0959-4493}}&lt;/ref&gt; use.  Oral [[vitamin E]] or [[omega-3 fatty acid|omega-3]] and [[omega-6 fatty acid]]s are also used.  More refractory cases may require the use of oral [[nicotinamide|niacinamide]] and [[tetracycline]] or immuno-suppressive medication such as [[corticosteroid]]s, [[azathioprine]], or [[chlorambucil]].&lt;ref&gt;{{cite journal |vauthors=Griffies J, Mendelsohn C, Rosenkrantz W, Muse R, Boord M, Griffin C |title=Topical 0.1% tacrolimus for the treatment of discoid lupus erythematosus and pemphigus erythematosus in dogs |journal=J Am Anim Hosp Assoc |volume=40 |issue=1 |pages=29–41 |year=2004 |doi=10.5326/0400029 |pmid=14736903}}&lt;/ref&gt;  Treatment is often lifelong, but there is a good [[prognosis]] for long-term [[remission (medicine)|remission]].

==Commonly affected dog breed==
*[[Alaskan Malamute]]
*[[Collie]]
*[[German Shepherd Dog]]
*[[Shetland Sheepdog]]
*[[Siberian Husky]]
*[[Brittany (dog)|Brittany]]
*[[German Shorthaired Pointer]]&lt;ref name=Griffin_2001/&gt;
*[[Africanis]]
*[[Rottweilers]]

==References==
{{Reflist}}

[[Category:Dog diseases|Discoid lupus erythematosus]]
[[Category:Autoimmune diseases]]