Derm 11 - more scaling Flashcards
primary cornification disorders
- timing / age of appearance
- origins
- management general strategy
- possible distributions
- often start early in life - genetically determined
- lifelong “control vs cure”
- may be multifocal and generalized or localized
primary seborrhea
- breeds
- appearance
- etiology
- age
- distribution
- type of sebborrhea variance
- connection to other condition?
- Dx
- Tx
Most common breeds:
- american cocker spaniel
- English springer spaniel
- West highland white terrier
- basset hound
<><>
- Often associated with
ceruminous otic discharge and a hyperplastic otitis externa, greast, malodorous skin, follicular casts, digital hyperkeratosis and dry brittle claws
<><>
- Increased epidermal cell turnover rate (8 days vs 21 days)
- suspected to be an autosomal recessive mode of inheritance
- early age of onset – severity increases with time
<><><>
- Face, neck, paws perineum and ventrum are particularly affected
- Type of seborrhea may vary with breed – may be dry and scaly in a Doberman and greasy in a Cocker.
<><>
- Increased predisposition to Malassezia dermatitis
<><>
- Diagnosis: rule out secondary scaling disorders and support with biopsy
<><>
- Treatment: Topical therapy, antibiotics as needed, EFA supplementation
sebaceous adenitis
- etiology / origin
- breeds, species
- age of onset
- presentation
- Idiopathic cell mediated destruction of the sebaceous gland
- Autosomal recessive in Poodles and Akitas but many breeds are be affected
- Seen in numerous species including the cat and the rabbit
- Any age of onset but most common in young adult to middle age
<><>
Presentation, general: - Lesions often start on the dorsum
- Convex pinna is commonly affected with fine scales noted
<><>
Short Coated breed presentation:
> Areas of scaling that enlarge peripherally and may coalesce
> Moth eaten appearance without evidence of folliculitis
<><>
Long coated breed presentation
> Hair coat may change in colour as the first sign and then change in texture (e.g. Curly
hair may become straight)
> Follicular casts and fronds
> Secondary folliculitis and furunculosis
sebaceous adenitis Dx
Histopathology
– in some cases the diagnosis is made due to the absence of sebaceous gland
> older, alopecic lesions are less likely to see an inflammatory reaction at the sebaceous glands; biopsy of an early active lesion is best to see the inflammatory reaction on the sebaceous glands.
- Short coated dogs may have larger granulomatous lesions.
sebaceous adenitis treatment
- treat secondary infections
- Bath oil treatments
> topical application of baby oils, 1:1, leave on for a couple hours. Then shampoo with a degreasing shampoo (3X), then condition
> weekly shampoos for the first month, then frequency is slowly decreased - Co-administration with Vitamin A, Evening Primrose oil and omega 3 and 6 fatty acids round out the treatment protocol
- cyclosporine
- propylene glycol
- keratolytic and keratoplastic shampoo
Vitamin A Responsive Dermatosis
- breed
- age of onset
- presentation
- Most commonly seen in Cocker Spaniels but has also been described in a Labrador Retriever and a miniature schnauzer. A case was reported in a group of Gordon setters as well
- adult onset
- medically unresponsive seborrheic skin disease associated with comedones, follicular casts and fronds, especially on the ventrum and lateral chest.
> Ceruminous otitis is commonly present as well
Vitamin A Responsive Dermatosis Tx, when to expect things to get better? monitoring?
- topical therapy
- antibiotics as needed
- EFAs
- Vitamin A 625- 800 IU/kg PO q 24h
> usually lifelong
> improvement noted by 3 weeks, remission 8-10 weeks
> monitor liver enzymes and tear production
zinc responsive dermatosis
- etiology
- why we see clinical signs
<><>
- syndrome 1 - what is it, who is affected, age of onset
- syndrome 2 - what is it, cause, breeds
- can be hereditary or secondary to a dietary imbalance
- Zinc absorption is also negatively affected by essential fatty acid deficiency, elevated levels of iron in water, or prolonged diarrhea.
<><> - It is suspected that low zinc levels cause poor lytic enzyme function (thus affecting epidermal maturation) or increased epidermal turnover rate (leading to hyperkeratosis).
<><><><>
Syndrome I:
o Hereditary. Genetic defect involving zinc absorption reported in Alaskan malamutes.
o Age of onset is typically 1-3 years; range
o Many dogs with syndrome 1 develop lesions September to January
o Northern canine breeds, such as Alaskan malamute, Siberian husky, and Samoyed; also reported
in Doberman pinschers and Great Danes;
o Lethal acrodermatitis due to a genetic defect in zinc absorption has been described in bull terriers
o There is a report of severe zinc responsive dermatosis in Pharaoh hounds that required intravenous zinc supplementation
<><>
Syndrome II: most common in young, rapidly growing dogs
o Dietary. Diets high in calcium or phytates (plant/grain products) bind zinc, decreasing absorption.
o Any breed; Great Dane, Doberman pinscher, beagle, German shepherd, German short-haired pointer, Labrador retriever, Rhodesian ridgeback, and standard poodle may be predisposed.
o Rapidly growing puppies fed diets deficient in zinc or high in phytates (high plant/grain content) or
calcium
zinc-responsive dermatosis presentation - lesions, sites
o Scaling and crusting dermatosis.
o Pruritus may precede development of other clinical signs and is present in nearly half of cases.
o Focal cutaneous erythema and alopecia progress to scaly and crusted lesions.
o Secondary microbial (bacterial and yeast) dermatitis
o Predilection sites: periocular, ears, bridge of the nose, perioral, footpads, pressure points on limbs.
scrotum, prepuce, perianal region, and vulva may also be affected.
o Dull, dry coat
o Some puppies with syndrome II present with depression, anorexia, delayed growth, fever, and
lymphadenopathy.
zinc responsive dermatosis Dx
o Skin biopsy: epidermal parakeratotic hyperkeratosis is the most common finding, and follicular
parakeratosis is highly suggestive.
o Identification of lesions both clinically and histopathologically in an animal of a breed that is at risk, an animal that has a current history of nutritional inadequacy (high in phytates, high iron-content drinking water), or an animal with chronic diarrhea.
zinc-responsive dermatosis syndrome 1 treatment
- elemental zinc supplementation
> low dose steroids sometimes needed to aid absorption
Schnauzer Comedo Syndrome
- what is this
- Dx
- Tx
o Acne in breed predisposed individuals that form over the back possibly due to a developmental dysplasia of the hair follicles
o Diagnosis often made by the clinical presentation but can be confirmed by biopsy
o Control versus cure disease - topical antiseborrheic treatment .
> Try milder treatments first and then step
up as needed, Twice weekly shampoo for the first month and then decrease as needed
canine ichthyosis
- etiology
- breeds
- what characterizes this disease
- notable at birth
- clinical signs, locations affected
- Tx
- Congenital disease characterized by excessive scaling
- various breeds can be affected, most commonly Jack Russel, Golden retriver, Westie, Norfolk terrier, Soft coated wheaton, american bulldog, cavalier king charles spaniel
- Epidermal skin cell turnover time may be as short as about 3 1⁄2 days, twice as long as a pet with primary
seborrhea and significantly faster than the average 3-week turnover time - for the most part, dogs appear normal at birth
- Scaling dermatosis of varying severity; the scales are more adherent in sparsely haired areas and the
scales ride up the hair shafts in more haired areas - Intertriginous and flexural areas are particularly affected as well as the nasal planum and digital pads
which may be markedly feathered - Treatment is as all scaling dermatosis and the owner needs to know that this is a lifelong condition
general treatment reccomendations for scaling disorders
- goal
- for primary?
- The goal of treatment is to address the underlying etiology specifically if possible
- In primary conditions, it is important to control secondary microbial dermatitis while controlling the amount of scale produced
> Systemic antibiotics until resolution of clinical signs or until improvement plateaus (usually a minimum of 4 weeks) if a bacterial component is suspected - Some animals require chronic treatment
general treatment reccomendations for scaling disorders
- general things that can help
- Essential fatty acid (EFA) oral supplementation
> adjunctive
<><> - Systemic and topical antifungal treatment as needed
<><> - Topical therapy: clipping of hair coat may benefit topical therapy:
> Antiseborrheic shampoos contain keratolytic and/or keratoplastic compounds and are used initially twice weekly
> Good choices of ingredients for dry, scaly coats include sulfur and salicylic acid;
> Topical antiseborrheic products containing phytosphingosine may be of benefit
<><> - Greasy skin in dogs can be degreased using products containing benzoyl peroxide, selenium sulfide, or tar
<><> - others, depending on condition
