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Dermatology - Misc Ulcerative Alopecic Scaling Dermatoses

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sihirlifil's version from 2017-09-25 23:25

Miscellaneous Ulcerative

Question Answer
Canine familial dermatomyositis: signalment?Young dogs
Collies/Shelties predisposed
Canine familial dermatomyositis: Clinical findings?Usually skin only (sometimes muscle)- shiny, glistening, looks like scar tissue, Sharpie outline
Not painful or pruritic
Waxes and wanes in spite of tx
Canine familial dermatomyositis: dxHistopath
Canine familial dermatomyositis: Treatment optionsSupportive
Tx of choice: Pentoxifylline- helps bring O2 to lesion (deforms RBCs to get into smaller tissue spaces), anti-inflammatory, used for vasculitis
Glucocorticoids?
Cutaneous T-cell lymphoma: signalment?Old dogs
Cutaneous T-cell lymphoma: Clinical findings?Haired skin and mucosa: Ulcers in mouth, progressive erythema --> scaling --> full-blown nodules, masses
Intense pruritis
Cutaneous T-cell lymphoma: diagnosis?R/o bacteria & demodex via biopsy
Cytology: lots of big ugly cells
Cutaneous T-cell lymphoma: treatment?CCNU (Lomustine) can cure
Vogt-Koyanagi-Harada: wtf is it?Aka uveodermatologic syndrome
Severe anterior uveitis (blindness), depigmentation, ulceration; rapidly progressive
Vogt-Koyanagi-Harada: leukoderma & leukotrichia? Poliosis?Whitening of skin and hair coat
Poliosis = gray coloration of skin
Vogt-Koyanagi-Harada: tx?Glucocorticoids
Juvenile cellulitis: presents how?Crusting, scaling, deep tissue cellulitis, thick face & muzzle, huge lymph nodes (can open/rupture), fever
Juvenile cellulitis: age onset?VERY YOUNG, magic cutoff at 16 weeks
Juvenile cellulitis: DdxPyoderma
Demodicosis
Dermatophyte
Autoimmune
Juvenile cellulities: diagnosis?Rarely biopsy, dx based on CS & r/o bacteria, demodex, dermatophyte
Juvenile cellulitis: tx?Corticosteroids until remission then taper off (relapses uncommon) (Anti-inflammatory doses don't touch it)
Cephalexin (especially with open LNN)
Keep isolated
Don't vax with such high dose of steroids (immunosuppressed)
Juvenile cellulitis: prognosis?Permanent scarring, but respond to therapy quickly
Vasculitis =Inflammation of blood vessels
Vasculitis: CS?"Weird lesions" (variable)
Severe crusting, skin doesn’t blanche, target lesions, erythema, central pallor
Vasculitis: Ddx?Ehrlichia
Drug eruption (clavamox)
Vaccine
Insect reaction
Bacteria
Dermatophyte
Food allergy
Vasculitis: diagnosis?Histopathology
Vasculitis: tx?Varies based on underlying problem
Corticosteroids CONTRAINDICATED
Pentoxifylline
(Doxycycline if ehrlichia)
Pinnal vasculitis: distribution?Vasculitis of only ear margins usually symmetrical
Pinnal vasculitis looks like?Crusting, ears bleed when dog shakes head (tiny blood vessels rupture)
Pinnal vasculitis: tx?NOT STEROIDS! Causes vessels to become more friable (catabolic)
Pentoxifylline tx of choice
Rabies vax-induced alopecia: what happens?Give rabies vax, develop transient vasculitis affecting hair follicles
Never see the reaction, but see the scar tissue months later. Risk of developing systemic vasculitis
Erythema multiforme =Necrosis of keratinocytes
Erythema multiforme: caused by?Adverse drug reaction (in-class example clavamox)
Idiopathic
Toxic epidermal necrolysis =Essentially full-body erythema multiforme (open wounds across entire surface of skin)
Toxic epidermal necrolysis: what causes it?Topical therapies/adverse drug reactions
What can you do to help toxic epidermal necolysis?Apply sugar to wounds (helps granulation)
Bandaging
Toxic epidermal necrolysis: tx options?Remove cause
Pain management (lidocaine drip, topical fentanyl)
Supportive
Toxic epidermal necrolysis: prognosis?Can be guarded... costs a lot
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Miscellaneous Alopecic

Question Answer
Pattern baldness occurs when?After puberty- born normal
Pattern baldness: breed predispositions?Mostly daschunds, chihuahuas
Presentation of pattern baldness:Permanent hair loss of pinna & ventrum (and other), tends to be symmetrical
Pattern baldness: what happens to the hair follicle?Become mineralized! Hair follicles still there, just tiny (Not scar-like as in rabies vax)
Diagnosis of pattern baldnessDiagnosis by exclusion (e.g. Ddx hypothyroid, easy to r/o)
Think endocrine as first ddx
Color dilute alopecia: aka? what is it?“Color mutant” alopecia or “Blue Doberman Syndrome”
Hair is normal at birth --> macromelanosomes within hair, clump up and damage cuticle, sterile folliculitis
Color dilute alopecia: treatment options?Benzoyl peroxide shampoo (helps clean follicle): scrub, leave on for 10 minutes, careful b/c it dries out skin and bleaches
Moisturizers (esp w/ benz perox)
Fatty acids
Antibiotics if 2ry infection
Encourage not to breed
Black hair follicle dysplasia: Breed predispositions?Any breed
affects only black hairs!
Black hair follicle dysplasia: Diagnosis?Endocrine alopecia tends to be…
Endocrine alopecia tends to be…Bilateral, symmetrical
Other concurrent signs- hyperpigmentation, UTI, etc
Hair follicles of endocrine alopecia are in ___ stageTelogen
Hypothyroidism presents how?Lethargy, myxedema, “tragic look” from ground substance in dermis getting puffy
“Rat tail” ddxHypothyroid, Cushings
Only pruritic endocrine disorder =Hyperestrogenism
How to treat hyperestrogenism?Spay the bitch
Endocrine skin disorders (5)Hypothyroidism
Hyperadrenocorticism
Hyperestrogenism
Hypotestosterone
Castration responsive
Seasonal flank alopecia: Breed predispositions?Short-coated breeds (English bulldogs, pit bulls...)
Seasonal flank alopecia: Distribution? Lesion?Bilateral but NOT SYMMETRICAL! Hyperpigmentation
Seasonal flank alopecia: primary rule out?Hypothyroid (same age, similar presentation)
Rule out hypothyroid = diagnosis
Alopecia X: aka? what’s going on?Pseudo-Cushings
Growth hormone & castration responsive, adrenal sex hormone alopecia
Alopecia X: predisposed?Pomeranian, Chow chow, Keeshond, Samoyed (thick hair coats); Intact males
Alopecia X: CS?Alopecia (duh), hairs that remain are brittle, regresses to puppy coat, hyperpigmentation. Cosmetic disease
Alopecia X: treatment options?(Melatonin...doesn't work)
Castration
Benign neglect
*Key points for diagnosing?Rule out everything else
Biopsy
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Cornification Disorders

Question Answer
Scaling is almost always…Secondary to an underlying cause and finding it will lead to resolution of the problem
Hyperkeratosis =Increased keratin
Orthokeratosis =Corneocytes are mature
Parakeratosis =Corneocytes retain their nucleus; zinc-responsive type of disease
Seborrhea sicca = ? Oleosa?Sicca = dry scale
Oleosa = greasy
The 1 primary cause of scaling mentioned:Ichthyosis
The ‘almost primary’ causes of scaling:Idiopathic seborrhea of cocker spaniels
Sebaceous adenitis
(Causes of scaling: Ectoparasites)Flea
Cheyletiella
Demodex
Scabies
(Causes of scaling: Nutritional)Zinc responsive
Vitamin A responsive
Fatty acid deficiencies
(Causes of scaling: Congenital/hereditary)Ear margin seborrhea
Ichthyosis
Cocker spaniel seborrhea
(Causes of scaling: Infectious)Bacterial
Viral
Dermatophyte
Malassezia
Lice
(Causes of scaling: Metabolic/endocrine)Hypothyroidism
Hyperadrenocorticism
Lymphoma
Adverse drug eruption
Autoimmune
(Causes of scaling: Environmental)Humidity
Bathing/topical meds
Keratolytic =Decrease cohesion between corneocytes (make scale microscopic, wash it off)
Keratoplastic =Renormalization of cornification (downregulate system, change rate of growth & turnover)
(Damage to skin: increases cell turnover)
Active ingredients:Sulfur
Salicylic acid (usually sulfur & sal. acid are together)
Benzoyl peroxide
Zinc (good for Malassezia!)
What should you always do as part of your diagnostics?DEEP SCRAPE! Don’t miss Demodex!
Antiseborrheics:Sulfur (keratolytic & keratoplastic)
Salicylic acid (keratoplastic)
Emollient =Thick, greasy softening agents
Examples of emollientsOils, waxes, lanolin, petrolatum
Humectant =Draw moisture to stratum cornea
Examples of humecetantsPropylene glycol
Colloidal oatmeal
Urea
Lactic acid
Nasal hyperkeratosis: CS?Lots of scale building up
Nasal hyperkeratosis: treatment?Break down keratin w/ vaseline (safe, cheap, humectant)
Biobalm (contains essential oil)
Pad hyperkeratosis: Diagnosis?If biopsy, just see keratin
Pad hyperkeratosis: Treatment?Trim, humectants
Ear margin seborrhea: looks like? Ddx?Scale buildup at ear margins, not inflammatory or painful. Ddx vasculitis
Ear margin seborrhea: Treatment?Avoid steroids
Cleanse
(Not pathologic problem)
Ichthyosis: how does it happen? Breeds?Congenital & hereditary (genetic causes)
Golden retriever (especially puppy! check them well), Norfolk terrier, others (llama)
Ichthyosis: diagnosis?Biopsy
Noninflammatory, hyperkeratosis
Treatment of ichthyosis?Supportive :/
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