Skin - pyoderma, fungal skin diseases, normergic dermatitis Flashcards
(22 cards)
Pyoderma is usually caused by:
- Coagulase positive staphylococci:
- -> Staph. pseudointermedius
- -> Staph. aureus
- -> Staph. schleiferi
- Coagulase negative staph.
- micrococci
- less frequent by:
- -> alpha-hemolsysis strept.
- -> gram - rods: pseudomonas aeruginosa, proteus vulgaris, E.coli
Types of Pyoderma
- Surface pyoderma (involves the superficial horny layer - str. corneum)
- Acute moist dermatitis, pyotraumatic dermatitis, hot spot
- skin fold pyoderma (intertrigo) - Superficial pyoderma
- Impetigo (juvenile pustular dermatitis, puppy pyoderma, nonfollicular pustule)
- superficial folliculitis - Deep pyoderma (bacterial infection of the skin beneath the hair follicle involving both dermal and subcuticular tissues - furuncle: rupture of follicle)
- muzzle, chin folliculitis and furunculosis (canine acne)
- nasal pyoderma
- interdigital pyoderma (pododermatitis)
- pressure point pyoderma (callus pyoderma)
- GS pyoderma
- pyotraumatic folliculitis
- generalized deep folliculitis, furunculosis and cellulitis
Surface pyoderma:
- Acute moist dermatitis, pyotraumatic dermatitis, hot spot
- any (long haired) breeds + hot, humid weather
- self trauma perpetuates the problem: (itch-lick-chew cycle)
- lesions develop rapidly
- several underlying causes (e.g. flea, otitis, paraproctitis, neurosis)
- Treatment:
- eliminate the underlying cause!
+ clipping, shampoos (disinfacting, drying) short term CS + antibiotics topically
(parenterally)
Surface pyoderma:
- skin fold pyoderma (intertrigo)
- anatomical „defects”: warm+ humid + dark microenvironment + self-trauma
- Types:
- lip fold: c. spaniels
- facial fold: brachycephalic breeds
- vulvar fold pyoderma: obese, too early spayed bitches
- tail fold pyoderma: corkscrew tail
- body fold pyoderma
-generalized: shar-pei - Treatment:
- plastic surgary or
everyday cleansing by disinfectant, drying powder, solutions, suspensions, shampoos (benzoil-peroxid)
Superficial pyoderma:
- Impetigo (juvenile pustular dermatitis, puppy pyoderma, nonfollicular pustule)
- subcorneal (beneath str corneum) pyoderma:
- on the face, ventral abdomen, and axilla pustules, papules, and yellow crusts
- young puppies prior to puberty
- may be asymptomatic
- underlying problems:
- ectoparasites, endoparasites
poor nutrition, unhygienic environment - Treatment:
- treat the underlying cause,
+ antibacterial shampoos (ethyl-lactate, chlorhexidine,(benzoyl peroxide) in every 2-4 days
for 2 weeks, then +/- antibiotics (but NO CS!!!)
Superficial pyoderma:
- Superficial folliculitis
- bacterial infection at the level of the intact hair follicle or at the epidermis immediately below the str. corneum
- any age, but more common in young dogs
- variable lesions:
- papules, pustules with hair protruding, crusts, epidermal collarettes, “moth-eaten” alopecia +/- pruritus
- IT IS ALWAYS SECONDARY PROBLEM (atopy, FA, parasites, endocrine disorders, immunosuppression, etc.)
- Treatment:
- underlying cause, antibacterial drugs for min 3 weeks systematicly, + topically (but NO CS!!!)
Deep pyoderma:
- what can cause it
- Staphylococcus pseudintermedius +/- other bacteria (Pseudomonas aeruginosa, Proteus vulgaris, Escherichia coli)
+ underlying cause always present (demodicosis, foreign body, dermatophyte infection, endocrine disorder, immunodeficiency, CSs)
Deep pyoderma:
- muzzle, chin folliculitis and furnculosis (canine acne)
Great danes, boxers, Dobermann, Hungarian Vizsla
Treatment: systemic antibacterial drugs + topical
Deep pyoderma:
- nasal pyoderma
- doliocephalic breeds
- treatment: antibiotics 6+x+2 weeks, elisabethan collar
Deep pyoderma:
- interdigital pyoderma (pododermatitis)
- short coated breeds
Underlying factors: e.g.: - foreign body, Demodex, atopy, trauma
Clinical signs: The feet may be swollen, painful, discharged pus, alopecia due to licking, paronychia;
In chronic cases: nodules, ulceration, fistulae, furunculosis
Treatment: treat the underlying cause, surgical drainage,
bathing the feet in saline, systemic antibact. therapy autogenous vaccines, immunestim. (?) e.g. levamisole
Deep pyoderma:
- Pressure point pyoderma (callus pyoderma)
Occurrence: large breed dogs:
- elbows, hocks, sternum
- The skin thickens, then if repeated trauma:deep pyoderma
Treatment: antibacterial drugs, + check for underlying problems (soft bed)
Deep pyoderma:
- GS pyoderma
Lesions:
- papules, pustules, furunculosis, hyperpigmentation, alopecia
Localization:
- gluteal region, ventral abdomen, dorsum, thighs (generalized)
Deep pyoderma:
- pyotraumatic folliculitis
golden/labrador retrievers, St. Bernards, rottweiler
mimics acute moist dermatitis
no response on cleansing and CS-therapy
Deep pyoderma:
- generalized deep folliculitis, furunculosis and cellulitis
- This is the most severe type of deep pyoderma underlying factors are present!
- The lesions occur anywhere but especially pronounced on the trunk and ventral abdomen
- Treatment: very long antibacterial therapy (iv!!!),
+ whirlpool bathing + immunostimulation+ underlyings
Classification of Fungal skin diseases
- superficial mycosis
- subcutaneois mycosis
- systemic mycosis
Superficial mycosis:
- dermatophytosis (ringworm)
- dogs and cats
- etiology: microsporum canis, M. gypseum, M. persicolor. Trichophyton mentagrophytes, T. verrucosum, T. terrestre
- direct contact/contaminated materials from the environment
- zoonosis
- Clinical signs:
- Dogs: patchy alopecia, plaques, folliculitis, scales, crusts, (nails)
- Cats: ‘cigarette-ash’-like, patchy alopecia, miliary dermatitis, crusts,
Can be ASYMPTOMATIC! And/or LESIONS ON THE OWNER!
* Self limiting disease in healthy animals (lack of immunity?)
• Diagnosis: most accurate diagnosis: culturing !!!
- (dermatophyte test medium (DTM))
• (Wood’s lamp, KOH preparations by microscopy, biopsy (PAS staining)
Superficial mycosis
- Malassezia pachydermatitis (pityrosporum canis)
- normal commensal of the ears –> otitis externa
- usually secondary to: allergodermatitis, endocrinopathies, etc.
- rarely generalized dermatosis by itself:
- alopecia, scaling, pruritic –> seborrhoea, lichenification
- Diagnosis: cytology (Diff-Quick staining)
(IF microscopy, culture – sample in test medium to send)
Types of Normergic dermatitis
- Primary irritant contact dermatitis (normergic dermatitis)
- Nasal solar dermatitis (collie-nose dermatitis = DLE= Discoid lupus erythematosus)
- burns
- frost bite
Normergic dermatits:
- Primary irritant contact dermatitis:
- must be different form contact hypersensitivity, more common than contact hypersensitivity
- Etiology:
- Absolute cause: acids and alkalis
- Relative cause: detergents, soaps, solvents
- flea collars (fitted too tightly); or can be allergic against it
- Clinical signs:
- localization: any area where the hair is sparse; ventral surface of the abdomen, axilla, interdigital space, perineum, scrotum
- Treatment:
- find the irritating substance and remove it
- bathing
- topical CS-ointments
Normergic dermatits
- Nasal solar dermatitis (Collie-nose dermatitis = Discoid lupus erythematosus)
- Cause: unknown, collies are predisposed, phototoxic reaction to UV radiation; seasonal occurence in the early stages with increasing severity by the time going
- Localisation: in unpigmented skin (nose, eyelipds, lips)
- Clinical signs:
- erytherma, alopecia around the nose, crusting, ulceration, exudation (risk! squamous cell carcinoma)
- Treatment:
- avoid sunlight, use topical GC, and PABA-containing sunscreen agents
Normergic dermatits
- burns
- Types:
- Full thickness: destruction of the epidermis + adnexa
- parial thickness: reepithelization is possible secondary pyoderma is common
- Clinical signs:
- pain, skin over the affected area becomes dry and hard (secondary infections)
- if necrosis is on > 25% of the body surface: systemic illness
- Treatment:
- remove necrotic tissue, gentle bathing and cleaning, hydrating, pain killer (opioids, NSAIDs not enough), hepatic support
Normergic dermatits
- Frost bite
- Occurrence: rare, -30*C for prolonged times
- Common sites: tips of the tail, ears, scrotum, toes
- Treatment: thaw rapidly in warm water, topical antibact creams, surgical debridement
