Hair, swabs and impressions

What are the clinical signs which indicate a need for skin sampling

• Alopecia

• Otitis

• Pruritis

• Erythema

• Seborrhea

• Pyoderma

• Uticaria

• Atopy

• Hyperkeratosis

• pododermatitis

What dies alopecia mean

Hair loss

What does otitis mean

Ear infection

What does pruritic mean

Itching

What does pyoderma mean

Skin infection

What does erythema mean

Redness

What does seborrhoea mean

Flaky skin

What does pododermatitis mean

Foot infection

What does atopy mean

Allergic skin disease

What does urticaria mean

Hives

What does hyperkeratosis mean

Excess growth of the horny layer of the epidermis

What equipment for tape impression

• Gloves 

• Clippers 

• Tape 

• Slides 

• Diff quick 

• Immersion oil 

• Microscope 

What method tape impression

• Apply tape onto skin area 

• Ensure to not to touch sticky side of tape  

• Rub tape with thumb nail  to ensure good contact  

• Stick on the slide  

• Diff-quick  

• Can be examined under oil immersion for bacteria and yeast 

What does tape impression analysis X4/X10/X40 diagnose

• superficial ectoparasites

  • fleas

  • flea dirt

  • lice

  • cheyletiella

  • otodectes and eggs

  • harvest mite 

What does tape analysis X100 diagnose

• Oil immersion lense

• Bacteria  

• Fungi-spores 

• Yeasts e.g. Malassezia 

• Cells e.g. neutrophils 

What are tape impression advantages

• Non-invasive 

• Cheap and easy 

• Not very stressful 

• Can access harder to reach areas e.g. skin folds 

What are tape impression disadvantages

• Contamination 

• Miss burrowing parasites 

• Uncomfortable 

• Hard to get large population 

What equipment direct impression

• Gloves 

• Clippers 

• Needles-pick off scabs etc  

• Slides  

• Diff-quick 

• Immersion oil  

• Microscope   

What method direct impression

• Good for exudative lesions  

• If non –exudative can be ‘picked’ with a needle to express fluid  

• Gently press the slide onto the lesion  

• Air-dry  

• Stain with diff-quick  

• Examine on low power first then high power/oil immersion  

what analysis direct impression

• Detection under X100 objective lens oil immersion 

• Bacteria, Fungi and Yeast 

• Inflammatory cells: neutrophils, eosinophils.  lymphocytes, macrophages   

• Pre-histology smears from biopsies  

• Can diagnose mast cell tumours sometimes 

What are direct impression advantages

• Non-invasive 

• Cheap and easy 

• Not very stressful 

• Good for moist lesions 

• Good for dectetion of microorganisms 

What are direct impression disadvantages

• Only surface sample

• Not good for hard to reach areas 

• Slide can snap if patient moves 

What equipment hair brushing

• Gloves  

• Flea comb 

• Hairbrush 

• White paper  

• Paraffin  

• Slides  

• Coverslips  

• Diff-quick  

• Microscope   

What method hair brushing

• Brush hair over black consulting table or white/brown paper for 5 minutes  

• Place hairs in petri dish, cover in liquid paraffin  

• Place scale/parasites on slide with liquid paraffin 

• Apply cover slip  

• Examine under microscope   

• For fleas-putting suspected flea excrement on moistened paper towel and if present will turn a reddish brown 

What analysis hair brushing

• X10 X40 objective lens 

• Superficial ectoparasites

  • fleas

  • flea dirt

  • cheyletiella

  • lice   

What are hair brushing advantages

• Non-invasive 

• Not very stressful 

• Quick, cheap and easy 

• Easy diagnosis for surface ectoparasites 

What are hair brushing disadvantages

• Miss burrowing parasites 

• Not good for cytology 

What equipment hair pluck

• Gloves 

• Forceps  

• Slides  

• Paraffin-helps visualise parasites 

• Cover slips  

• Microscope

Trichography-examing hair follicle

• Use forceps to pluck hair in an alopecic area  

• Place onto a slide and evaluate under low power 

What can you see when hair plucking

What are advantages of hair pluck

 

• Quick, cheap and easy 

• Can detect demodex, mites and fungal infections 

• Good for hard to access areas 

What are disadvantages hair pluck

• Not good for surface parasites 

• More uncomfortable 

• Not good for cytology 

• Temperament needs to be considered

What equipment skin scrapes

• Gloves 

• 10 blade 

• Slides 

• Coverslips 

• Parafin 

• Microscope 

What can you diagnose with skin scrape superficial

• On every pruritic/scaly patient 

• May be able to diagnose demodex 

• Can diagnose 

  • Cheyletiella 

  • Sarcoptes scabei 

  • Notoedres cati 

What method deep skin scrape

• Suspected demodex 

• Must scrape on 5 or more locations 

• Squeeze prior to scrapinf, scrape util capillary oozing 

• Diagnose demodex including juveniles and eggs 

Where to do scraping

• Head and neck-otodectes 

• Lateral elbow/lateral hock/pinnae -sarcoptes scabi, notoedres cati,

• Dorsum/ areas of dandruff/scal- cheyeletiella 

• Alopecia margins- demodex 

• Comedones-demodex 

 

What are skin scrape advantages

• Quick, cheap and easy 

• Good for diagnosing demodex and burrowing parasites 

• Samples the epidermis 

• Only method to diagnose some deep parasites e.g. sarcoptes 

 

What are skin scrape disadvantages

• More uncomfortable 

• Some may need sedation 

• Invasive 

• Not good for surface parasites e.g. lice and fleas 

• Not good for cytology 

• Can cause secondary infection as have caused a wound 

• Patient interference 

What equipment swabs

• Gloves 

• Plain swabs/cotton buds 

• Slides 

• Cover slips 

• Diff quick 

• Microscope 

What method swabs

• Rub swab over skin/ gently around external ear  

• If dry area swab or location can be premoistened with saline/paraffin 

• Roll swab along slide 

• Can also suspend large blobs of earwax in paraffin   

• Add cover slip  

• Examine under microscope  

What diagnose swabs x4/x10

• Otodectes cynosis

What diagnose swabs x100

• Fungi- Ringworm- moist swab 

• Yeast- Malassezia  

• Bacteria: In house cytology smear OR external culture and sensitivity 

• Inflammatory cells;  

  • Initial inflammatory cells: neutrophils, eosinophils 

  • Chronic inflammation: macrophages, lymphocytes   

What are swab advantages

• Quick and easy

• Can detect bacteria and fungal infections 

• Good for hard to access areas e.g. ears 

• Good for moist/deep lesions 

What are swab disadvantages

• Not good for parasites 

• Can be uncomfortable 

• Risk of contamination 

 

What is woods lamp

• UV lamp to detect skin problems

• A screening not a diagnostic test 

• Always requires follow up testing such as trichogram/culture/PCR 

What are advantages of woods lamp

• Easy 

• Non-invasive 

• Quick 

• Rapid diagnosis of dermatophyte infections, especially in felines 

What are disadvantages woods lamp

• False +ve and false –ve's 

• 30%-70% sensitivity for microsporum canis-false negatives 

• Microscporum gypseum and trichophyton mentagrophytes do not fluoresce 

• Lint, dander and organic debris can fluoresce= false +ve 

 

What do we label samples with

• Site sample 

• Method used 

• Prior topical/systemic acaricide(s)/antiparasitic treatment or antifungal(s) used 

 

When do we choose each method

• Pruritis and scaling- skin scrape, tape impression 

• Suspected demodex-hair pluck or skin scrape 

• Exudative lesion- swab, direct impression 

• Suspected dermatophyte- Tape impression, direct impression