Skin 6 - Systemic Disease

Front 1

drug eruptions are common and may mimic many other skin conditions. theys may be immune mediated or non immune. discuss immune mediated and non immune

Back 1

immune mediated- hypersensitivity to the drug.
non immune- predictable side effects or interactions with other drugs/ unpredictable - idiosyncratic, pseudo-allergic or an intolerance.

Front 2

at what stage in life are genetic disorders of the skin usually seen ?

Back 2

may not appear to 4-5 years of age

Front 3

what broad things might cause nutritional skin disease

Back 3

lack of somthing in the diet/ malabsorption/ antimetabolites/ defective use

Front 4

what might be the obvious clinical signs of protein, FA or vitamin deficiency

Back 4

protein- poor hair coat/ immunodeficiency leading to infection.

FAs- diffuse scaling / alopecia

vitamin - scaling and or alopecia / dermatitis in some

Front 5

what sp is zinc responsive dermatosis seen in mostly, what is zinc needed for and what are the clincial signs seen. what breeds and age of dog are predisposed to it. hoe might the diet of pigs cause it. what disease may present with similar signs.

Back 5

esp. pigs and dogs.

zinc is needed for enzymes which regulate RNA and DNA metabolism. ( tissue growth , maturation and repair/ Vit A metabolism/ free radical scavanging / inflammation and immune response)

decreased wound healing/keratinisation defects in epidermis, hair, horn / parakeratosis ( retained Nucleus) eg periorbital crusting

nordic breeds due to presumed inherited malabsorption. Puppies of any breed due to cereal diet or generic dog food.

pigs food containing phytate/ high calcium/ low FAs in cereal based diets will decrease the available zinc.

hepatocutaneous syndrome ( small nodular liver)

Front 6

describe the various symdromes in which zinc deficiency is though to play a role and explain the method thought to be involved

Back 6

swine parakeratosis ( a true zinc deficiency due to diet-pigs food containing phytate/ high calcium/ low FAs in cereal based diets will decrease the available zinc.

zinc responsive dermatosis in goats and dogs ( mechanism uncertain in goats. dogs- nordic breeds due to presumed inherited malabsorption. Puppies of any breed due to cereal diet or generic dog food.

SND ( superficial necrolytic dermatitis - a combination of deficiencies including zinc, AAs and FAs due to may reasons- diet insuficiency/malabsorption/ disorders of metabolism/ liver disease/ elevated glucagon.

lethal acrodermatitis of bull terriers- inherited autosomal recessive disorder thought to be caused by a defect in zinc metabolism. 'acro' means extremities eg the foot.

Front 7

what is the most common cause of superficial necrolytic dermatitis ans what is a consistent feature irrespective of cause

Back 7

liver disease. also glucagonoma.
hypo-amino-acidaemia is a consistant feature.

Front 8

what are the symptoms of lethal acrodermatitis of bull terriers

Back 8

dead by age 2 - 'lethal'

affects extremities- 'acro' eg distorted swollen foot with crusted pads.

stunted growth - think of zincs role

small or absent thymus - again think of the role of zinc in immunity - so suceptible to skin /lung/intestinal infections

Front 9

give examples of exactly how skin lesions may indicate internal disease giving specific examples

Back 9

influenced by hormone levels/ overall health.
endocrine, paraneoplastic or systemic diseases.
A skin biopsy can be used to make a diagnosis of internal disease.

eg endocrine related Alopecia ( glycocorticoids or oestrogens will cause supression/ Thyroid hormone will cause accleration. )

Front 10

what is telogen effluvium and anogen effluvium

Back 10

telogen effuvium may follow cytotixic therapy or other stress ( tempory hair loss due to sheding of resting hair - abruptly shifted from anogen. The loss will occur some time later ( weeks or months ) when new hairs start to grow. ( CLUB SHAPED TIP )

Anagen effluvium is similar but the onset is rapid due to sudden inhibition of cell proliferation by drugs toxins or inflammation. ( POINTED TIP)

Front 11

name the types of systemic diseases which may affect the skin

Back 11

immune and autoimmine diseases/ circulatory diseases /drug irruptions/ genetic disorders/ metabolic, endocrine or nutritional diseases/ neoplastic and paraneoplastic syndromes.

Front 12

define the terms anogen, catogen, telogen and effluvium

Back 12

anogen- growth phase
catogen- transition phase
telogen- resting phase
effluvium -shedding

Front 13

list all types of disease that may cause alopecia, give an example of each

Back 13

endocrine ( eg canine cushings syndrome)

genetic - colour dilution alopecia causes follicle displasia

immune mediated/auto - aloppecia areata in horses and dogs mostly - monunclear cell infiltrate

paraneoplastic- eg pancreatic carcinoma

neoplastic - cutaneous lymphoma- atypical cell infiltrate

inflammatory -COMMON-dermal inflammation and or scarring eg leishmaniasis ( protozoa)- crusting and alopecia

breed associated cyclic flank alopecia eg in boxers

Front 14

give an example of paraneoplastic skin disease and describe the skin lesions and give an example of neoplastic disease which causes alopecia.

Back 14

paraneoplastic syndrome- feline paraneoplastic alopecia ( rare and associated with malignant tumors on viscera , usually the pancreas. appears as ventral hair loss with shiny skin)

and many others....Cushing’s syndrome; alopecia, calcinosis cutis - eg caused by pituitary adenoma
Feline exfoliative dermatitis-Thymoma
Feline paraneoplastic alopecia-Pancreatic adenocarcinoma
Feminisation syndrome-Sertoli cell tumour
Paraneoplastic pemphigus-Lymphoma, thymoma
Superficial necrolytic dermatitis-Glucagonoma


neoplasia- cutaneous lymphoma - bilateral/ symmetrical and non pruritic alopecia

Front 15

give examples of endocrine related alopecia in dogs and cats stating their cause and presentation both clinically and histologically.

Back 15

Juvenile onset pan-hypo-pituitarism ( aka pititary dwarf. seen in GSDs. autosomal recessive trait. maformed or cystic pituitary gland. notice when pup is about 2 months old due to slower growth, retained puppy coat and lack of primary hairs, gradual development of bilateral and symmetrical alopecia. histology- atrophic dermatitis with hairless telogen follicles.

cushings disease more in adults ( hyper-adrenocorticism- signs relate to gluconeogenic, lipolytic, protein catabolic, and anti-inflammatory effects of the glucocorticoid hormones
.Atropic dermatitis with comedones and bilateral symetrical alopecia, thin skin and pot bellied appearance. also calcinosis cutis- cutaneous calcification- which is uncommon but caracteristic )

hypothyroidism ( mainly in dogs but over diagnosed and controversial skin signs which may be subtle - alpecia, dry skin, increased mucin makes skin thicker)

sertoli cell tumor

Front 16

describe breed associated alopecia

Back 16

Canine cyclic flank alopecia-aka seasonal flank alopecia, recurrent flank alopecia
Boxer, Bulldog, Airdale terrier, Schnauzer etc.
Tardive onset, most cases regrow hair but condition is progressive in some individuals.
Photoperiod – pineal gland - melatonin may influence development. Histology: Hair cycle arrest / hair follicle dysplasia

Or

Canine Follicular Dysplasia
Syn. hair follicle dysplasia
Siberian Husky, Irish Water Spaniel, Portuguese Water Dog, etc.
Features vary between breeds (non-cyclical)
Pathogenesis uncertain- may be linked to steroidogenesis
Histology: variable hair cycle arrest; follicle atrophy / dysplasia-pigmentary incontinence / pigment clumping

Front 17

describe colour dilution alopecia in dogs. ( breeds, cause)

Back 17

aka blue dog syndrome. A genetic alopecia.
seen in dilute coated dogs of various breeds.
there is a delay in onset so breeding control is dificult.
caused by inherited folicular dysplasia.
the dilute hairs fail to grow and the tan colour will grow normally- opposite to black hair folicular dysplasia

Front 18

describe the cause of alopecia areata

Back 18

Autoimmune alopecia.
Pathogenesis includes infiltration of hair bulbs by T-lymphocytes = ‘Bulbitis’ resulting in the classic ‘swarm of bees’ appearance.
most often in dogs and horses. Hair loss may be localised or generalised.