Sebaceous adenitis
Encyclopedia
In canines, sebaceous adenitis, or SA, refers to the autoimmune disease
found in some breeds of dog and more rarely in cats, rabbits and horses. It is an uncommon, idiopathic
skin disease, characterised by an immune response against the dog's sebaceous glands (glands found in the hair follicles in the skin dermis
), which can lead to the destruction of the gland. It was first described in veterinary literature in the 1980s.
For long- or double-coated breeds such as Poodles, Akitas and Samoyeds, the condition often presents itself with silvery dandruff which adheres to the coat, hair loss (not to be confused with moulting or "blowing coat"), a dull and brittle coat, and later on skin lesions along the back and ears as well as thickened skin and a musty or rancid odour. For short-coated breeds such as Vizslas, the condition causes facial swellings, nodular skin lesions, fine dandruff which does not adhere to the coat, and a general "moth-eaten" appearance to the coat.
is a general term referring to the inflammation of a gland.
Breeds also mentioned in scientific literature as having some susceptibility include:
There has also been mention of the condition in cats, rabbits and horses.
Other conditions with similar presentations include: bacterial folliculitis and demodicosis
, dermatophytosis
, endocrinopathy, pemphigus foliaceus
, Zinc responsive dermatosis, vitamin A-responsive dermatosis, ichthyosis
, and nutritional deficiencies. As well as, superficial pyoderma
, primary idiopathic seborrhea
and other endocrine diseases.
drugs may be effective, and it is postulated, through some studies, that large doses of vitamin A given orally may result in some improvement.
It has been suggested in the paper by Angus (2009) that the more aggressively one applies the topical
methods of treatment, the less aggressively one needs to employ the immunosuppressant therapy. The suggestion is that this phenomenon may be due to a cyclic feedback whereby secondary infection, when not aggressively treated with topical therapy, increases and contributes to further sebaceous gland inflammation.
. The mineral oil soak, whereby the oil remains on the affected animal for at least 2 hours, is needed to replace epidemal lipids as well as to restore normal epidermal barrier function. The oil is then removed through the process of many baths. This oil treatment needs to be repeated at least once a week for 4 to 7 weeks until new hair growth is observed. Once new hair growth is observed, topical treatment can be decreased to every 2 to 4 weeks.
Corticosteroids (e.g. Prednisone) are used only if puritus
is a major clinical feature, and is given at 2 mg/kg/day for 2 to 4 weeks and then tapered to withdrawal.
Autoimmune disease
Autoimmune diseases arise from an overactive immune response of the body against substances and tissues normally present in the body. In other words, the body actually attacks its own cells. The immune system mistakes some part of the body as a pathogen and attacks it. This may be restricted to...
found in some breeds of dog and more rarely in cats, rabbits and horses. It is an uncommon, idiopathic
Idiopathic
Idiopathic is an adjective used primarily in medicine meaning arising spontaneously or from an obscure or unknown cause. From Greek ἴδιος, idios + πάθος, pathos , it means approximately "a disease of its own kind". It is technically a term from nosology, the classification of disease...
skin disease, characterised by an immune response against the dog's sebaceous glands (glands found in the hair follicles in the skin dermis
Dermis
The dermis is a layer of skin between the epidermis and subcutaneous tissues, and is composed of two layers, the papillary and reticular dermis...
), which can lead to the destruction of the gland. It was first described in veterinary literature in the 1980s.
Description
Sebaceous adenitis is an autoimmune, inflammatory, skin disease of currently unknown cause. Research is currently underway to find if there is a genetic predisposition for SA, and the exact mode of inheritance remains unknown. However, it is postulated that it is an autosomal recessive acquired condition. It has no sex-predisposition. There are two expressions of this condition, one for long or double coated breeds and one for short coated breeds, both with differing presentations.For long- or double-coated breeds such as Poodles, Akitas and Samoyeds, the condition often presents itself with silvery dandruff which adheres to the coat, hair loss (not to be confused with moulting or "blowing coat"), a dull and brittle coat, and later on skin lesions along the back and ears as well as thickened skin and a musty or rancid odour. For short-coated breeds such as Vizslas, the condition causes facial swellings, nodular skin lesions, fine dandruff which does not adhere to the coat, and a general "moth-eaten" appearance to the coat.
Etymology
Sebaceous refers to the gland which is targeted by the immune system of affected animals. AdenitisAdenitis
Adenitis is a general term for an inflammation of a gland or lymph node.-Lymph node adenitis:"Lymph adenitis" or "lymph node adenitis" is caused by bacterial infection in lymph nodes. The infected lymph nodes typically become enlarged, warm and tender. A swelling of lymph nodes due to growth of...
is a general term referring to the inflammation of a gland.
Susceptibility of certain breeds of dog
While the condition has been seen in over 60 breeds of dog (including cross breeds), certain breeds have been found to be more susceptible than others to sebaceous adenitis:- American AkitaAmerican AkitaThe Akita is a large spitz breed of dog originating from the mountainous northern regions of Japan. There are now two separate strains: American, a/k/a "Akita" or "American Akita"; and Japanese, aka "Akita Inu" or "Japanese Akita"...
and Akita Inu - Standard PoodlePoodleThe Poodle is a breed of dog. The poodle breed is found officially in toy, miniature, and standard sizes, with many coat colors. Originally bred as a type of water dog, the poodle is highly intelligent and skillful in many dog sports, including agility, obedience, tracking, and even herding...
- Viszla
- Springer SpanielSpringer SpanielSpringer Spaniel refers to two different breeds of dogs, both of which are commonly called simply Springer Spaniel:*English Springer Spaniel*Welsh Springer Spaniel...
- Chow ChowChow ChowChow chow is a breed of dog that was developed in China, where it is referred to as Songshi Quan , which literally means "puffy-lion dog".- Appearance :...
- SamoyedSamoyedSamoyed may refer to:* the Samoyedic peoples in Siberia who speak the Samoyedic languages: the Enets, the Nenets, the Nganasans, and the Selkups* the Samoyedic languages they speak* Samoyed , a dog breed...
- WeimaranerWeimaranerThe Weimaraner is a dog that was originally bred for hunting in the early 19th century. Early Weimaraners were used by royalty for hunting large game such as boar, bear, and deer. As the popularity of large game hunting began to decline, Weimaraners were used for hunting smaller animals like...
- HavaneseHavaneseThe Havanese is a dog breed of the Bichon type, developed from the now extinct Blanquito de la Habana . The Blanquito descended from the also now extinct Bichon Tenerife, which was introduced to the Canary Islands by the Cubans...
Breeds also mentioned in scientific literature as having some susceptibility include:
- German Shepherd DogGerman Shepherd DogThe German Shepherd Dog , also known as an Alsatian or just the German Shepherd, is a breed of large-sized dog that originated in Germany. The German Shepherd is a relatively new breed of dog, with its origin dating to 1899. As part of the Herding Group, the German Shepherd is a working dog...
- DachshundDachshundThe dachshund is a short-legged, long-bodied dog breed belonging to the hound family. The standard size dachshund was bred to scent, chase, and flush out badgers and other burrow-dwelling animals, while the miniature dachshund was developed to hunt smaller prey such as rabbits...
- Old English SheepdogOld English SheepdogThe Old English Sheepdog is a large breed of dog which was developed in England from early herding types of dog. The Old English Sheepdog has very long fur covering the face and eyes...
- Lhasa ApsoLhasa ApsoThe Lhasa Apso is a non-sporting dog breed originating in Tibet. It was bred as an interior sentinel in the Buddhist monasteries, who alerted the monks to any intruders who entered...
- BoxerBoxer (dog)Developed in Germany, the Boxer is a breed of stocky, medium-sized, short-haired dog. The coat is smooth and fawn or brindled, with or without white markings. Boxers are brachycephalic , and have a square muzzle, mandibular prognathism , very strong jaws and a powerful bite ideal for hanging on to...
- CollieCollieThe collie is a distinctive type of herding dog, including many related landraces and formal breeds. It originates in Scotland and Northern England. It is a medium-sized, fairly lightly built dog with a pointed snout, and many types have a distinctive white pattern over the shoulders. Collies...
- Toy PoodlePoodleThe Poodle is a breed of dog. The poodle breed is found officially in toy, miniature, and standard sizes, with many coat colors. Originally bred as a type of water dog, the poodle is highly intelligent and skillful in many dog sports, including agility, obedience, tracking, and even herding...
- Mixed-breedsMixed-breed dogA mixed-breed dog, also known as a mutt or mongrel, is a dog whose ancestry is generally unknown and that has characteristics of two or more types of breeds. A mixed-breed may be a cross-breed dog, a random-bred dog, or a descendant of feral or pariah dog populations...
There has also been mention of the condition in cats, rabbits and horses.
Diagnosis
In general, SA in canines is underdiagnosed. It has however been described in more than 60 breeds of dog as well as mixed breeds. Diagnosis confirmation requires multiple punch biopsies analysed by a dermopathologist who will comment on the condition of the sebaceous glands, revealing granulomatous or pyogranulomatous inflammation surrounding the sebaceous glands or even comple destruction of sebaceous glands.Other conditions with similar presentations include: bacterial folliculitis and demodicosis
Demodicosis
Demodicosis, also called demodectic mange or red mange, is caused by a sensitivity to and overpopulation of Demodex canis as the animal's immune system is unable to keep the mites under control....
, dermatophytosis
Dermatophytosis
Dermatophytosis or ringworm is a clinical condition caused by fungal infection of the skin in humans, pets such as cats, and domesticated animals such as sheep and cattle. The term "ringworm" is a misnomer, since the condition is caused by fungi of several different species and not by parasitic worms...
, endocrinopathy, pemphigus foliaceus
Pemphigus foliaceus
Pemphigus foliaceus is an autoimmune blistering disease of the skin and mucous membranes with characteristic lesions that are scaly, crusted erosions, often on an erythematous base...
, Zinc responsive dermatosis, vitamin A-responsive dermatosis, ichthyosis
Ichthyosis
Ichthyosis is a heterogeneous family of at least 28, generalized, mostly genetic skin disorders. All types of ichthyosis have dry, thickened, scaly or flaky skin...
, and nutritional deficiencies. As well as, superficial pyoderma
Pyoderma
Pyoderma means any skin disease that is pyogenic. These include superficial bacterial infections such as impetigo, impetigo contagiosa, ecthyma, folliculitis, Bockhart impetigo, furuncle, carbuncle, tropical ulcer, etc. Autoimmune conditions include pyoderma gangrenosum...
, primary idiopathic seborrhea
Seborrhoeic dermatitis
Seborrhoeic dermatitis is an inflammatory skin disorder affecting the scalp, face, and torso. Typically, seborrheic dermatitis presents with scaly, flaky, itchy, and red skin. It particularly affects the sebaceous-gland-rich areas of skin...
and other endocrine diseases.
Treatment
There is no cure for this condition. Treatment is generally life-long and takes the form of bathing and soaking in mineral oils and washing with antibiotic shampoos to try to alleviate symptoms and slow the condition's progression. Antiseptic and antibiotic shampoos (chlorhexidine or benzoyl peroxide) are used to manage further secondary bacterial infection. For some breeds, cyclosporine or corticosteroids and immunosuppressantImmunosuppressant
An immunosuppressant is any substance that performs immunosuppression of the immune system. They may be either exogenous, as immunosuppressive drugs, or endogenous, as ,e. g., testosterone...
drugs may be effective, and it is postulated, through some studies, that large doses of vitamin A given orally may result in some improvement.
It has been suggested in the paper by Angus (2009) that the more aggressively one applies the topical
Topical
In medicine, a topical medication is applied to body surfaces such as the skin or mucous membranes such as the vagina, anus, throat, eyes and ears.Many topical medications are epicutaneous, meaning that they are applied directly to the skin...
methods of treatment, the less aggressively one needs to employ the immunosuppressant therapy. The suggestion is that this phenomenon may be due to a cyclic feedback whereby secondary infection, when not aggressively treated with topical therapy, increases and contributes to further sebaceous gland inflammation.
Topical Therapy
This forms a major and critical part in the disease treatment and the shampoo treatment can need to be applied as often as 3 to 4 times per week. An antiseborrheic shampoo removes the scale blocking the foliclesHair follicle
A hair follicle is a skin organ that produces hair. Hair production occurs in phases, including a growth phase , and cessation phase , and a rest phase . Stem cells are principally responsible for the production of hair....
. The mineral oil soak, whereby the oil remains on the affected animal for at least 2 hours, is needed to replace epidemal lipids as well as to restore normal epidermal barrier function. The oil is then removed through the process of many baths. This oil treatment needs to be repeated at least once a week for 4 to 7 weeks until new hair growth is observed. Once new hair growth is observed, topical treatment can be decreased to every 2 to 4 weeks.
Immunosuppressant Therapy
Immunosuppressant and anti-inflammatory therapy serves to stop on-going destruction of the sebaceous glands. Like other immune-mediated diseases, most animals receive an initial course to stop the inflammation and treatment is tapered off to the lowest dose that keeps the disease in remission. Initially, oral cyclosporine is given in doses of 5 mg/kg twice daily and then gradually decreased in frequency.Corticosteroids (e.g. Prednisone) are used only if puritus
Itch
Itch is a sensation that causes the desire or reflex to scratch. Itch has resisted many attempts to classify it as any one type of sensory experience. Modern science has shown that itch has many similarities to pain, and while both are unpleasant sensory experiences, their behavioral response...
is a major clinical feature, and is given at 2 mg/kg/day for 2 to 4 weeks and then tapered to withdrawal.
Dietry Supplementation
These are commonly included in treatments of SA and include:- Omega 6 Fatty Acids (e.g. Safflower or sunflower oil)
- Omega 3 Fatty Acids (e.g. Fish olis)
- Vitamin A at 8,000 to 10,000 IU twice daily and up to 20,000 to 30,000IU twice daily, not exceeding 1000IU/kg/day, if no improvement is seen within 3 months.
External links
Not used in Article- http://www.vin.com/VINDBPub/SearchPB/Proceedings/PR05000/PR00094.htm General clinical introduction. Accessed 08/April 2011
- http://www.petmd.com/dog/conditions/skin/c_dg_sebaceous_adenitis?page=2 For an introduction to the topic. Accessed 08/April 2011
- http://www.upei.ca/~cidd/Diseases/dermatology/sebaceous%20adenitis.htm General FAQ. Accessed 08/April 2011
- http://www.edliny.com/Encyclopedy/Veterinary%20Focus/181/2.pdf More advanced introduction, diagnosis and treatments. Accessed 08/April 2011
- http://www.vetwest.com.au/skin-deep-issue-so-whats-difference-between-canine-and-human-skin Explanation of the differences between Human and Canine skin. Accessed 12/April/2011