Alopecia Flashcards

Question

Dermatophytosis - less common species

Answer 1

▪Microsporum gypseum (geophilic; inhabits soil) ▪Trichophyton mentagrophytes (zoophilic ;reservoir rodents) ▪Trichophyton benhamiae (zoophilic; guinea pigs and rodents) ▪Only very rarely human ringworm (anthropophilic; reservoir people) causes disease in animal species.

Answer 2

Zoophilic – animal to animal Geophilic – environment to animal Anthropophilic – person to person

Answer 3

- scale and associated alopecia ▪Multifocal patches often circular ▪typical size 4-6 cm ▪+/- hyperpigmentation ▪Follicular casts ▪Mostly non-pruritic -- Not itchy unless get secondary bacterial infection ▪Often the head, ears and chin

Answer 4

- multifocal alopecia becomes confluent and is complicated by secondary bacterial pyoderma - therefore do cytology even in proven cases

Answer 5

- Trichophyton - can resemble deep pyoderma clinically

Answer 6

Wood’s lamp examination ▪Warm for 5-10 mins, expose hair for 3-5 mins ▪ Apple green fluorescence of hair ▪ Most M. canis fluoresce, if done carefully Trichography ▪ Arthrospores (soap bubbles) surrounding hair shaft, hyphae within hair, squashed & broken hairs In house DTM ▪ False positives and negatives ▪ If get colour change quickly it’s the fungi eating the protein, but must be in the 1st few days of culture ▪ If get colour change later (e.g. 10 days later) likely to be something from the environment ▪ Difficult to do so don’t bother External lab fungal culture (± PCR) ▪ Test of choice/gold standard Sampling for culture best using a sterile toothbrush = Mackenzie Technique DTM = dermatophyte test medium

Answer 7

▪Don’t prep the skin site ▪Send tissue with hair follicles ▪Deep wedge or excisional for nodular or indurated tissue, (debulk/excise nodules prior to treatment} ▪Alert laboratory to differential diagnoses – PAS / other fungal stains ▪In cases of nodular dermatophytic disease, biopsy is needed for diagnosis

Answer 8

▪ Can spontaneously resolve (12 -20 weeks) ▪ Clipping ▪ Topical treatment ▪ Environmental decontamination ▪ Systemic therapy

Answer 9

- but should be treated to reduce environmental contamination and zoonotic risk

Answer 10

▪ Controversial (? in long coated breeds) microtrauma may increase infection ▪ Remove a large number of the spores but also do tiny damages to the epidermis ▪ Particularly in Persian cats then means you can get subcortical dz or further infection in the hair follicles.

Answer 11

▪ Decreases contamination & speeds clinical cure ▪ Chlorhexidine* / miconazole shampoo (2– 3 times a week) ▪ Enilconazole in dogs (not licensed in cats) every 4 days * Note Chlorhexidine scrub or shampoo by itself is not effective These bring down the chances of the environment being contaminated but don't penetrate into the hair follicle well so doesn’t treat the active infection. Itraconazole or ketoconazole for this.

Answer 12

▪ M. canis viable for up to 18 months ▪ Isolate animal to 1 room (ideally non- porous surfaces) ▪ Destroy bedding or disinfect (bleach, chlorhexidine), use protective clothing & daily vacuuming and disinfection: sodium hypochlorite (bleach) 1:10 solution

Answer 13

▪ Necessary to achieve mycological cure ▪ Itraconazole (cats & dogs), ketoconazole (dogs) ▪ Variable adverse effects of ketoconazole in dogs, so unlicenced itraconazole used by some authors -- Ketoconazole has lots of adverse liver and GI effects

Answer 14

▪Monitor fungal culture every 2 weeks ideally using toothbrush technique --Start when obvious reduction in clinical lesions --Require two negative cultures 2 weeks apart to describe mycological cure --False positives will be noted if continuing high levels of environmental contamination --False negatives will be seen if very recent topical therapy before sampling ▪Once a week sampling used in some rescue catteries to increase throughput

Answer 15

- Yes - Transferred from dam in early life

Answer 16

= long bodied ▪Demodex canis (dog) ▪Demodex injai (dog) -- Massive ones -- tend to live on the. back -- cause a more greasy surface ▪Demodex cati (cat)

Answer 17

= short bodied ▪Demodex gatoi (cat) -- Causes very itchy skin dz -- Stands out because demodex (before secondary infection) is not contagious and is not itchy ▪Demodex cornei (dog) described but is considered a variant of D. canis and not a separate species and should not be used

Answer 18

- juvenile onset - adult onset

Answer 19

▪Immunosuppressive disease ▪ Idiopathic ▪Localised becoming generalised ▪Often generalised ▪Often secondary bacterial infection -- Papules, pustules, draining sinus tracts, enlarged lymph nodes, +/- pyrexia -- Pruritic or painful ▪Require aggressive treatment -- For demodex whilst also trying to work out what is causing it ▪This is most often a manifestation of profound systemic illness – but demodicosis may precede overt signs ▪ Seen in cats, dog, humans & otters -- Causes death in otters as they can't stay waterproof

Answer 20

▪Immature immune system -- Allows over proliferation of the DNA in the follicles ▪Localised (<6 patches alopecia) ▪Generalised (> 6 patches, or includes the feet, often multiple body regions) ▪Localised to generalised patches -- Alopecia -- Scaling -- Blue-grey hyperpigmentation -- Comedones -- Follicular casts ▪+/- superficial bacterial infection ▪Mild cases spontaneously resolve Alopecia, scale and erythema, comedones are obvious in most cases

Answer 21

Treat cases of localised disease when ▪Significant bacterial infection (antibiotic stewardship) ▪‘Accidentally if using isoxazolines for routine flea control ▪Not necessary for mild disease

Answer 22

Clinical appearance ▪Multifocal alopecia with follicular castings ▪Comedone formation ▪Secondary bacterial infection, often associated with peripheral lymphadenopathy ▪Malodour ▪Greasiness Positive skin scrapings, hair plucks or biopsy Reserve biopsy for areas with severe secondary changes (e.g. feet) or dogs with mucinosis (i.e. Sharpei)

Answer 23

- follicular dz

Answer 24

▪Demodicosis ▪Dermatophytosis ▪Sebaceous adenitis

Answer 25

▪Bacterial folliculitis ▪Other diseases -- e.g early ECL ▪Can be seen by eye

Answer 26

- feet and face

Answer 27

- skin scrapings

Answer 28

▪Hyperadrenocorticism ▪Hypothyroidism ▪Diabetes mellitus ▪Systemic neoplasia ▪Immunosuppressive therapy ▪FIV / FeLV Can also be iatrogenic -> use of steroids

Answer 29

▪Hereditary mite-specific immune defect? ▪Lifelong treatment ▪Small number juvenile cases progress to adulthood

Answer 30

▪Clip long haired animals, bathe to remove debris ▪Treat any secondary bacterial pyoderma ▪Treat ANY underlying immunosuppression ▪Anti-mite treatments -- Amitraz (Aludex®): licensed (not cats), not recommended -- ****Licenced isoxazoline drugs e.g. afoxolaner, flurolaner, sarolaner and lotilaner**** -- Imidacloprid/moxidectin (Advocate®): licensed, many have questioned the efficacy of this product in more severe cases ▪No need for environmental therapy -- As doesn't live off animal ▪Treat until 2-3 consecutive negative skin scrapes taken every 4 weeks ▪Neuter female dogs with generalised juvenile onset demodicosis -- Increased chance of disease in offspring -- Periparturient reduction in immunity can result in return of disease (demodicosis has a genetic basis and most likely multiple genes are involved)

Answer 31

▪Disease in young dogs that does not self-cure? ▪Involvement of more than 6 areas? ▪Involvement of any feet? ▪A judgement call

Answer 32

▪Follicular mites - rare cause of disease (c.f. dogs)

Answer 33

- eyelids - periocular - head or neck - ceruminous otitis

Answer 34

Immunosuppression, e.g. - FIV - FeLV - DM - HAC - SCC in situ

Answer 35

- comedones - alopecia - erythema - crust and scale - variable pruritus - secondary infection

Answer 36

- deep skin scrapes

Answer 37

- Isoxazolines (e.g. Flurolaner (Bravecto spot-on) or Selemectin & sarolaner (Stronghold Plus) - Selemectin alone will not kill demodex

Answer 38

- sebaceous adenitis - dermatomyositis - alopecia areata

Answer 39

- no - they are all rare

Answer 40

- Inflammation of the sebaceous glands - Subtle loss of truncal hair becomes more generalised - Some dogs presented for pruritus (due to 2 ̊ infection) or severe scale - Marked follicular casting - Akita, poodle particularly affected - Diagnosis by rule outs and biopsy

Answer 41

- Loss of hair from face and bony prominences (may be ulceration) - Cellular immune-mediated damage to epidermis and muscles - Often collie breeds - Diagnosis by rule outs and biopsy

Answer 42

- Rapid hair loss followed by incomplete regrowth of white hair -- the hair bulk contains large numbers of melanocytes, they get 2ndarily damaged in this so the hair grows back white - Presumed immune-mediated destruction of hair bulb - Trichogram: exclamation mark hairs - Diagnosis by rule outs and biopsy - Uncommon in dogs, common in Appaloosas

Answer 43

▪ photoperiod ▪temperature ▪ hormones -- thyroid (+ve) -- growth hormone (+ve) -- oestrogen (-ve) -- corticosteroids (-ve) ▪nutritional status ▪general health ▪growth factors ▪drugs

Answer 44

- anagen - catagen - telogen - exogen

Answer 45

- hair loss - 4th stage of the hair cycle

Answer 46

▪Endocrinopathies* -- Hyperadrenocorticism -- Hypothyroidism -- Hyper-oestrogenism: functional testicular/ovarian tumours -- Other sex hormone alopecias ▪Anagen/telogen defluxion ▪Paraneoplastic alopecia ▪Alopecia X ▪Cyclical flank alopecia ▪Post-clipping alopecia ▪Injection alopecia

Answer 47

 Changes in specific hormone ➔ telogenisation of hairs  Failure of regrowth when lost

Answer 48

- Flame follicles -- Caught in a strange catagen - Atrophic dermatopathy -- Wide telogenised follicles with reduced numbers of glands and thin epidermis

Answer 49

▪Symmetrical to generalised alopecia ▪Dull and dry coat (± scale) ▪Comedones ▪Hyperpigmentation ▪Atrophic skin -- When pinch skin it stays there -- This is not true to hypothyroidism ▪Poor wound healing ▪Post-clipping alopecia / poor hair growth

Answer 50

* Glucocorticoids effect on the skin➔catabolic and antimitotic effect * Decreased mitoses➔thinning, delayed wound healing, pilosebaceous atrophy * Inhibition of fibroblast proliferation, collagen and matrix substance production➔thinning, fragile vessels - Hair and glands reduced in size, so dry coat

Answer 51

Thyroid hormone ➔stimulation of cytoplasmic protein synthesis & increase tissue oxygen consumption * Initiation of anagen phase, wound healing * Decrease hair cell apoptosis – prolonged anagen phase * Promote matrix cell proliferation * Support development of lymphoid tissue, neutrophilic function, B- and T- lymphocyte function

Answer 52

- Sertoli cell tumour ▪More common in cryptorchid testes ▪Testicular discrepancy ▪Pendulous prepuce ▪Linear preputial erythema -- But this is not always present ▪Feminisation syndrome ▪Metastasis rare (local ln) ▪Rare myelosuppression ▪Neutering curative - Also interstitial cell tumours and rarely seminomas, but not Leydig cell tumours which produce testosterone

Answer 53

- sudden loss of hair - hairs are synchronised into telogen - shed as new hairs develop

Answer 54

Occurs 1–3 months post- stressful incident Pregnancy, lactation Severe illness Shock, surgery

Answer 55

- biopsy non-specific - need good history

Answer 56

- Pancreatic and bile duct carcinomas

Answer 57

- Older cats, often mildly systemically unwell - Alopecia of ventrum and legs - Skin shiny and translucent

Answer 58

- Aetiology unknown - Surgical excision curative -- Has to be early-stage disease -- Referral surgery - Poor prognosis -- Advanced disease at presentation -- Hepatic metastasis

Answer 59

▪Plush coated breeds (Pomeranians, Chow chows)

Answer 60

▪Unknown aetiology – local hormone aberrance? ▪genes coding for enzymes directly involved in sex hormones differentially regulated in alopecia X

Answer 61

▪Primary hairs lost first (puppy coat), later complete alopecia and hyperpigmentation ▪Spares extremities (eg. feet) and the head

Answer 62

▪Diagnosis of exclusion ▪Rule out endocrinopathies ▪Biopsy – follicular dysplasia versus atrophic pattern – flame follicles common ▪Sex hormone alopecia profile -- Very difficult to interpret – not a diagnostic pattern

Answer 63

▪No consistently effective treatment -- Neutering in males – temporary -- Dry-needling -- Melatonin -- Deslorelin acetate implant -- A cosmetic disease ▪Avoid use of mitotane or trilostane as high risk of adverse effects

Answer 64

- seasonal FA

Answer 65

- changes in day length ▪Reduction in day length, follicular atrophy & dysplasia ▪Alopecia seen as day length increases

Answer 66

▪Short coated bulldog, boxer type coat ▪Symmetrical as on both sides but not identical ▪Usually skin hyperpigmentation ▪Regrowth variable and can be progressive ▪Rule out HAC and hypoT4 – then skin biopsy ▪infundibular hyperkeratosis extends into 2 ̊ follicles, creating the shape of a witches’ foot ▪Melatonin used for treatment

Answer 67

▪Unknown – some form of follicular arrest

Answer 68

- plush coated breeds

Answer 69

- endocrinopathies -- HAC often presents this way - severe illness

Answer 70

- good - usually regrowth within 6m

Answer 71

Follicular atrophy with no inflammation (but may be immune mediated – vasculitis / panniculitis) - Focal alopecia +/- hyperpigmentation & atrophy - Usually local but may be remote from injection - Glucocorticoids, vaccines (esp. rabies), depot antibiotics - Usually spontaneously regresses - May be permanent scarring -- As can be enough vascular damage to cause this

Answer 72

1. Congenital alopecia 2. Pattern alopecia 3. Follicular dysplasia 4. Anagen defluxion/effluvium

Answer 73

- Defect in hair follicles -- Often associated with adnexal, epidermal, dental and nail defects -- Dominant, recessive, X-linked - Hairless breeds e.g. Mexican hairless, Chinese crested, Sphinx -- Dysplastic hair follicle can be prone to superficial and occasionally deep pyoderma (± sunlight damage) -- UV protection needed

Answer 74

▪Various syndromes – breed specific -- Later onset alopecia (2-3y+) -- Pre/post auricular, ventral neck, ventrum, caudal thighs -- Miniaturisation of hair -- Considerable concern for owners, but with low risk of secondary bacterial or yeast infections ▪Many breeds affected -- Yorkshire terrier (dorsal nose, ears and legs) -- Greyhound (back legs) -- Chihuahua -- Italian greyhound -- Dachshund (pinnae) -- Boston terrier -- Manchester terrier (bit of flank & face)

Answer 75

▪Greyhounds and other sighthound breeds -- Whippets, Galgo Español, and Magyar Agár

Answer 76

▪Genetic component likely -- 2019 - structural hair shaft defects associated with downregulation of genes and proteins essential for hair differentiation (so not a pattern alopecia) ▪Any age and sex may be affected ▪No treatment -- No vigorous shampooing/rubbing/grooming as will make the alopecia a lot worse

Answer 77

▪Bilateral hair loss on the caudal and lateral thighs ▪Alopecia may extend to the distal hind legs, the ventral abdomen and the chest and the ventral neck ▪May wax and wane

Answer 78

▪Familial disorder ▪Irish water spaniel, Portuguese water dog, curly coat retriever, Airedale, others

Answer 79

▪Dysplastic hair follicles -- Hairs fail to develop -- Shaft fractures -- Loose hair where traumatised ▪Progressive hair loss -- Breed specific & wear points ▪Regrowth of abnormal hairs ▪Bald neck or looks like they're wearing a bib ▪ Dysplastic hair follicles on biopsy ▪ Hard shampoo/tx can cause more damage

Answer 80

▪Familial disorder ▪One or more genetic defects in melanisation, e.g. incorrect transport of melanosomes into epithelial cells from melanocytes ▪Defect in pigmentation and hair formation

Answer 81

▪Progressive changes -- Born normal, coat changes by 4 weeks -- Black hairs become dull -- Hair fracture and loss ▪Bacterial infection in some cases ▪Normal white hair & broken alopecic dark hair areas

Answer 82

▪One or more genetic defects in melanisation ▪Macromelanosomes (melanin clumps cause hair fragility)

Answer 83

▪Affects dilute colour coats --Blue or fawn -- Established breeds with these colours rarely get this, e.g. Weimaraner, but the newer colours in breeds e.g. staffies, FBD, etc do ▪Progressive changes --Hair fracture and loss --Scaling -- +/- bacterial folliculitis

Answer 84

- based on signs, trichography, rule outs and possibly biopsy

Answer 85

- Sudden hair loss -- Chemotherapy -- Severe illness - Damage to growing hair/follicle - Patchy to complete hair loss -- Fractured/distorted hairs - Loss of whiskers

Answer 86

▪Avoid damage to coat -- Hairs prone to breakage -- May induce superficial pyoderma ▪High quality nutrition (including essential fatty acid supplementation) ▪Gentle anti-scaling shampoos ▪Prevent/treat secondary bacterial infection ▪Protect from sun ▪Melatonin is suggested? Efficacy unproven

Answer 87

comedones = blackheads - skin scrape as it's a follicular problem

Alopecia Flashcards

(113 cards)