Discoid lupus erythematosus (DLE) is an uncommon

autoimmune disease An autoimmune disease is a condition arising from an abnormal immune response to a functioning body part. At least 80 types of autoimmune diseases have been identified, with some evidence suggesting that there may be more than 100 types. Nearly a ...

of the

basal cell layer The ''stratum basale'' (basal layer, sometimes referred to as ''stratum germinativum'') is the deepest layer of the five layers of the epidermis, the external covering of skin in mammals. The ''stratum basale'' is a single layer of columnar or ...

of the

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...

. It occurs in humans and cats, more frequently occurring in

dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do ...

s. It was first described in dogs by Griffin and colleagues in 1979. 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 mucocutaenous CLE. It does not progress to systemic

lupus erythematosus Lupus erythematosus is a collection of autoimmune diseases in which the human immune system becomes hyperactive and attacks healthy tissues. Symptoms of these diseases can affect many different body systems, including joints, skin, kidneys, blo ...

(SLE) in dogs. SLE can also have skin symptoms, but it appears that the two are either separate diseases. DLE in dogs differs from SLE in humans in that

plasma cell Plasma cells, also called plasma B cells or effector B cells, are white blood cells that originate in the lymphoid organs as B lymphocytes and secrete large quantities of proteins called antibodies in response to being presented specific substan ...

s predominate

histologically Histology, also known as microscopic anatomy or microanatomy, is the branch of biology Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single ...

instead of

T lymphocyte A T cell is a type of lymphocyte. T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell rec ...

s. Because worsening of symptoms occurs with increased

ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than ...

light exposure, sun exposure most likely plays a role in DLE, although certain breeds (see below) are predisposed. After

pemphigus foliaceus Pemphigus foliaceus is an autoimmune blistering disease ( bullous disorder) of the skin. Pemphigus foliaceus causes a characteristic inflammatory attack at the subcorneal layer of epidermis, which results in skin lesions that are scaly or crusted ...

, DLE is the second most common autoimmune skin disease in dogs.

Symptoms

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.

Lesion A lesion is any damage or abnormal change in the tissue of an organism, usually caused by disease or trauma. ''Lesion'' is derived from the Latin "injury". Lesions may occur in plants as well as animals. Types There is no designated classifi ...

s may progress to

ulceration An ulcer is a discontinuity or break in a bodily membrane that impedes normal function of the affected organ. According to Robbins's pathology, "ulcer is the breach of the continuity of skin, epithelium or mucous membrane caused by sloughing o ...

and lead to tissue destruction. DLE is often worse in summer due to increased sun exposure.

Diagnosis

DLE is easily confused with solar dermatitis,

pemphigus Pemphigus ( or ) is a rare group of blistering autoimmune diseases that affect the skin and mucous membranes. The name is derived from the Greek root ''pemphix'', meaning "pustule". In pemphigus, autoantibodies form against desmoglein, whi ...

ringworm Dermatophytosis, also known as ringworm, is a fungal infection of the skin. Typically it results in a red, itchy, scaly, circular rash. Hair loss may occur in the area affected. Symptoms begin four to fourteen days after exposure. Multiple a ...

, and other types of dermatitis.

Biopsy A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a diseas ...

is required to make the distinction.

Histopathologically Histopathology (compound of three Greek words: ''histos'' "tissue", πάθος ''pathos'' "suffering", and -λογία ''-logia'' "study of") refers to the microscopic examination of tissue in order to study the manifestations of disease. Spec ...

, there is

inflammation Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...

at the

dermoepidermal junction The dermoepidermal junction or dermal-epidermal junction (DEJ) is the area of tissue that joins the epidermal and the dermal layers of the skin. The basal cells in the stratum basale of the epidermis connect to the basement membrane by the anchori ...

and degeneration of the basal cell layer. Unlike in SLE, an

anti-nuclear antibody Antinuclear antibodies (ANAs, also known as antinuclear factor or ANF) are autoantibodies that bind to contents of the cell nucleus. In normal individuals, the immune system produces antibodies to foreign proteins (antigens) but not to human pro ...

test is usually negative.

Treatment

Avoiding sun exposure and the use of sunscreens (not containing

zinc oxide Zinc oxide is an inorganic compound with the formula . It is a white powder that is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, food supplements, rubbers, plastics, ceramics, glass, cemen ...

as this is toxic to dogs) is important. Topical therapy includes

corticosteroid Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involv ...

and

tacrolimus Tacrolimus, sold under the brand name Prograf among others, is an immunosuppressive drug. After allogeneic organ transplant, the risk of organ rejection is moderate. To lower the risk of organ rejection, tacrolimus is given. The drug can also ...

use. Oral

vitamin E Vitamin E is a group of eight fat soluble compounds that include four tocopherols and four tocotrienols. Vitamin E deficiency, which is rare and usually due to an underlying problem with digesting dietary fat rather than from a diet low in vitami ...

omega-3 Omega−3 fatty acids, also called Omega-3 oils, ω−3 fatty acids or ''n''−3 fatty acids, are polyunsaturated fatty acids (PUFAs) characterized by the presence of a double bond, three atoms away from the terminal methyl group in their chem ...

and

omega-6 fatty acid Omega-6 fatty acids (also referred to as ω-6 fatty acids or ''n''-6 fatty acids) are a family of polyunsaturated fatty acids that have in common a final carbon-carbon double bond in the ''n''-6 position, that is, the sixth bond, counting from ...

s are also used. More refractory cases may require the use of oral

niacinamide Niacinamide or Nicotinamide (NAM) is a form of vitamin B3 found in food and used as a dietary supplement and medication. As a supplement, it is used by mouth to prevent and treat pellagra (niacin deficiency). While nicotinic acid (niacin) may b ...

and

tetracycline Tetracycline, sold under various brand names, is an oral antibiotic in the tetracyclines family of medications, used to treat a number of infections, including Acne vulgaris, acne, cholera, brucellosis, plague (disease), plague, malaria, and sy ...

or immuno-suppressive medication such as

azathioprine Azathioprine (AZA), sold under the brand name Imuran, among others, is an immunosuppressive medication. It is used in rheumatoid arthritis, granulomatosis with polyangiitis, Crohn's disease, ulcerative colitis, and systemic lupus erythematosus, ...

, or

chlorambucil Chlorambucil, sold under the brand name Leukeran among others, is a chemotherapy medication used to treat chronic lymphocytic leukemia (CLL), Hodgkin lymphoma, and non-Hodgkin lymphoma. For CLL it is a preferred treatment. It is given by mouth. ...

. Treatment is often lifelong, but there is a good

prognosis Prognosis (Greek: πρόγνωσις "fore-knowing, foreseeing") is a medical term for predicting the likely or expected development of a disease, including whether the signs and symptoms will improve or worsen (and how quickly) or remain stabl ...

for long-term remission.

Commonly affected dog breed

Alaskan Malamute The Alaskan Malamute () is a large breed of dog that was originally bred for its strength and endurance to haul heavy freight as a sled dog and hound. It is similar to other arctic breeds such as the husky, the spitz, the Greenland Dog, Canad ...

Collie Collies form a distinctive type of herding dogs, including many related landraces and standardized breeds. The type originated in Scotland and Northern England. Collies are medium-sized, fairly lightly-built dogs, with pointed snouts. Many ...

German Shepherd Dog The German Shepherd or Alsatian is a German breed of working dog of medium to large size. The breed was developed by Max von Stephanitz using various traditional German herding dogs from 1899. It was originally bred as a herding dog, for he ...

Shetland Sheepdog The Shetland Sheepdog, often known as the Sheltie, is a breed of herding dog that originated in the Shetland Islands of Scotland. The original name was ''Shetland Collie,'' but this caused controversy amongst Rough Collie breeders of the time, s ...

* Siberian Husky *

Brittany Brittany (; french: link=no, Bretagne ; br, Breizh, or ; Gallo language, Gallo: ''Bertaèyn'' ) is a peninsula, Historical region, historical country and cultural area in the west of modern France, covering the western part of what was known ...

German Shorthaired Pointer The German Shorthaired Pointer (GSP) is a medium to large sized breed of pointing dog developed in the 19th century in Germany for hunting. A versatile hunting breed, being an all-purpose gun dog suitable for both land and water, they are streaml ...

Africanis The Africanis is a dog landrace found across southern Africa. Description As is typical with landraces, there are several regional variations, believed to be the result of isolation and, to a limited degree, deliberate breeding. Some modern w ...

Rottweilers The Rottweiler (, ) is a Dog breed, breed of domestic dog, regarded as medium-to-large or large. The dogs were known in German as , meaning Rottweil butchers' dogs, because their main use was to herding dog, herd livestock and pull Dogcart (d ...

References

{{Reflist

Discoid lupus erythematosus Discoid lupus erythematosus is the most common type of chronic cutaneous lupus (CCLE), an autoimmune skin condition on the lupus erythematosus spectrum of illnesses. It presents with red, painful, inflamed and coin-shaped patches of skin with a sc ...

Autoimmune diseases