Discoid lupus erythematosus (DLE) is an uncommon autoimmune disease of the basal cell layer of the skin. It occurs in humans [1] and cats, more frequently occurring in dogs. It was first described in dogs by Griffin and colleagues in 1979. [2] [3] 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. [4] 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. [5] DLE in dogs differs from SLE in humans in that plasma cells predominate histologically instead of T lymphocytes. [6] 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. [7] After pemphigus foliaceus, DLE is the second most common autoimmune skin disease in dogs. [8]
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. [9] Lesions may progress to ulceration and lead to tissue destruction. DLE is often worse in summer due to increased sun exposure.
DLE is easily confused with solar dermatitis, pemphigus, ringworm, and other types of dermatitis. Biopsy is required to make the distinction. Histopathologically, there is inflammation at the dermoepidermal junction and degeneration of the basal cell layer. [8] Unlike in SLE, an anti-nuclear antibody test is usually negative. [5]
Avoiding sun exposure and the use of sunscreens (not containing zinc oxide as this is toxic to dogs [10] [11] ) is important. Topical therapy includes corticosteroid and tacrolimus [12] use. Oral vitamin E or omega-3 and omega-6 fatty acids are also used. More refractory cases may require the use of oral niacinamide and tetracycline or immuno-suppressive medication such as corticosteroids, azathioprine, or chlorambucil. [13] Treatment is often lifelong, but there is a good prognosis for long-term remission.
Pimecrolimus is an immunosuppressant drug of the calcineurin inhibitor class used in the treatment of atopic dermatitis (eczema).
Pemphigus 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 "blister".
Skin disorders are among the most common health problems in dogs, and have many causes. The condition of a dog's skin and coat is also an important indicator of its general health. Skin disorders of dogs vary from acute, self-limiting problems to chronic or long-lasting problems requiring life-time treatment. Skin disorders may be primary or secondary in nature, making diagnosis complicated.
Polymorphous light eruption (PLE) presents with itchy red small bumps on sun-exposed skin, particularly face, neck, forearms and legs. It generally appears 30 minutes to a few hours after sun exposure and may last between one and 14 days. The bumps may become small blisters or plaques and may appear bloody,often healing with minimal scarring.
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 scaly and crusty appearance, most often on the scalp, cheeks, and ears. Hair loss may occur if the lesions are on the scalp. The lesions can then develop severe scarring, and the centre areas may appear lighter in color with a rim darker than the normal skin. These lesions can last for years without treatment.
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, blood cells, heart, and lungs. The most common and most severe form is systemic lupus erythematosus.
Pemphigus erythematosus is simply a localized form of pemphigus foliaceus with features of lupus erythematosus.
Chilblain lupus erythematosus was initially described by Hutchinson in 1888 as an uncommon manifestation of chronic cutaneous lupus erythematosus. Chilblain lupus erythematosus is characterized by a rash that primarily affects acral surfaces that are frequently exposed to cold temperatures, such as the toes, fingers, ears, and nose. The rash is defined by oedematous skin, nodules, and tender plaques with a purple discoloration.
Tumid lupus erythematosus is a rare, but distinctive entity in which patients present with edematous erythematous plaque.
Subacute cutaneous lupus erythematosus is a clinically distinct subset of cases of lupus erythematosus that is most often present in white women aged 15 to 40, consisting of skin lesions that are scaly and evolve as poly-cyclic annular lesions or plaques similar to those of plaque psoriasis.
Lupus erythematosus panniculitis presents with subcutaneous nodules that are commonly firm, sharply defined and nontender.
Palisaded neutrophilic and granulomatous dermaititis (PNGS) is usually associated with a well-defined connective tissue disease, lupus erythematosus or rheumatoid arthritis most commonly, and often presents with eroded or ulcerated symmetrically distributed umbilicated papules or nodules on the elbows.
Lupus, technically known as systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Common symptoms include painful and swollen joints, fever, chest pain, hair loss, mouth ulcers, swollen lymph nodes, feeling tired, and a red rash which is most commonly on the face. Often there are periods of illness, called flares, and periods of remission during which there are few symptoms.
Postinflammatory hypopigmentation is a cutaneous condition characterized by decreased pigment in the skin following inflammation of the skin.
Acute cutaneous lupus erythematosus is a cutaneous condition characterized by a bilateral malar rash and lesions that tend to be transient, and that follow sun exposure. The acute form is distinct from chronic and subacute cutaneous lupus erythematosus, which may have different types of skin lesions. Cutaneous lupus erythematosus is associated with both lupus erythematosus-specific lesions and cutaneous manifestations that are not specific to lupus erythematosus, such as oral ulcers and urticaria. Because of the diagnostic criteria used to diagnose systemic lupus erythematosus, a patient with only cutaneous manifestations may be diagnosed with the systemic form of the disease.
Anti-SSA autoantibodies are a type of anti-nuclear autoantibodies that are associated with many autoimmune diseases, such as systemic lupus erythematosus (SLE), SS/SLE overlap syndrome, subacute cutaneous lupus erythematosus (SCLE), neonatal lupus and primary biliary cirrhosis. They are often present in Sjögren's syndrome (SS). Additionally, Anti-Ro/SSA can be found in other autoimmune diseases such as systemic sclerosis (SSc), polymyositis/dermatomyositis (PM/DM), rheumatoid arthritis (RA), and mixed connective tissue disease (MCTD), and are also associated with heart arrhythmia.
Ernst H. Beutner was a German-born microbiologist who discovered the role of autoimmunity in pemphigus and pemphigoid using self-designed immunofluorescent methods. For this achievement, he is often regarded as the "Founder of Immunodermatology". He was the author or co-author of over 10 papers, which were each cited over 100 times.
Rudi Harold Cormane was a Dutch dermatologist who pioneered research in immunofluorescence studies of the skin.
Autoimmune skin diseases occur when the immune system of an infected animal attacks its own skin. In dogs, autoimmune skin diseases are usually not detected until visible symptoms appear, which differs from detection in humans who are able to verbally express their concerns. Genetics, nutrition, and external environmental factors all collectively contribute to increasing the probability an autoimmune skin disease occurring. The severity of symptoms varies based on the specific disease present and how far it has progressed. Diagnosis often requires the onset of visible symptoms and for a biopsy to be performed. For many diseases, the condition itself cannot be cured, but a veterinarian can prescribe medications and other forms of treatment to help manage the symptoms of the dog.
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.
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.