Exam 2 - Pyoderma Flashcards
what is the most common agent involved in pyoderma?
staphylococcus pseudintermedius
what is pyoderma? why is it important?
pyogenic (pus-producing) bacterial infection of the skin
common cause of skin disease in companion animals - especially dogs
T/F: pyoderma is almost always occurring secondarily to an underlying cause
true
why does depth of infection matter?
dictates the appropriate duration of antibiotic therapy & helps guide treatment
how do we determine depth on skin infections?
diagnostic work up - look at lesion types, clinical signs, cytology/skin scrape, & biopsies
what is another name for pyotraumatic dermatitis?
hotspot
what is this lesion?
hot spot - pyotraumatic dermatitis
do you need systemic antibiotic therapy for superficial bacterial skin infections?
lecture she gave said no, but the notes state otherwise???
yes - required for most cases along side topical therapies
can you tell by looks alone that a patient has a methicillin-resistant staph infection?
nope
what is the difference between resident bacteria & transient bacteria in regards to the normal commensal organisms of the skin?
resident - capable of living & multiplying on normal skin
transient - not capable of multiplying on normal skin
commensal bacteria will not normally evoke an immune response from the host unless what?
conditions favoring overgrowth are occurring
______ bacterial skin conditions are uncommon while _______ bacterial skin conditions are common because of opportunistic pathogens
primary - uncommon
secondary - common
T/F: staphylococcus pseudintermedius is RARELY isolated from normal and diseased human skin/mucosa
true
what is the most common bacterial agent involved in human skin disease?
staph aureus
what is the pathophysiology of pyoderma?
bacterial adherence leads to colonization & penetration of abnormal skin which may produce/release enzymes & toxins which act as super antigens
what are some examples of alteration & function in the skin that lead to conditions allowing pyoderma to occur?
- faulty epidermal barrier function
- abnormal cutaneous microclimate
- aberrant immune response - either allergic response or immunosuppression
if you see cocci on skin cytology, what are you thinking?
staphylococcal bacteria until proven otherwise!!!!
T/F: often times, treating the staphylococcal component of a mixed infection with rod-shaped bacteria will result in clinical resolution of the pyoderma
true
what are the most common pathogens isolated from pyoderma in cats?
s. pseudintermedius & s. aureus
what are the agents involved in cat-bite abscesses?
pasteurella multocida (normal inhabitant of the mouth), strep spp., & anaerobic pathogens
how is canine pyoderma classified?
based off of the cutaneous depth of infection & appropriate duration of therapy
T/F: pyoderma is assumed to be related to staph spp unless there is a qualifier to denote otherwise
true
why are b-lactam antibiotics empirically prescribed for animals with superficial pyoderma/folliculitis? what are examples of drugs used?
most commonly associated with staph organisms & they have a wide spectrum of activity against staph spp - all used for at least 3-4 weeks, 1 week past clinical resolution
cephalexin 22-30mg/kg twice daily
cefpodoxime 10mg/kg once daily
clavamox 20mg/kg 3x a day
cefovecin 8mg/kg q 14 days
other than abscesses & cellulitis, other forms of what disease are not as common in cats when compared to dogs?
other forms of pyoderma
what diseases may mimic superficial bacterial folliculitis & deep pyoderma?
demodectic mange & dermatophytic folliculitis/furunculosis
when a dog has pyoderma, what should you immediately evaluate for?
concurrent demodicosis
if you treat a patient with empiric b-lactam antibiotics for superficial pyoderma, and they fail to respond, what should you do next?
culture the skin - need to exclude methicillin-resistant/multi-drug resistant organism
why do you need to do a culture for an animal with deep pyoderma?
the duration of systemic antibiotic therapy will be many weeks!!! be a good shepherd of antibiotics
what are some recognized diseases/conditions associated with surface depth pyoderma?
pyotraumatic dermatitis - hot spots
intertrigo
bacterial overgrowth syndrome
what are some recognized diseases/conditions associated with superficial depth pyoderma?
impetigo
superficial bacterial folliculitis (superficial pyoderma)
superficial spreading pyoderma (exfoliative superficial pyoderma)
mucocutaneous pyoderma
what are some recognized diseases/conditions associated with deep pyoderma?
deep bacterial folliculitis/furunculosis - nasal, chin, pressure point, pedal, & pyotraumatic
post-traumatic grooming furunculosis
cellulitis
acral lick dermatitis
what treatment is used for surface pyoderma? are systemic antibiotics indicated?
may only require topical therapy to remove excessive bacteria/sebum until clinical signs resolve & topicals are used for maintenance therapy once the infection is controlled!!
not really - topicals are your friend here
what is the minimum treatment duration for systemic antibiotics when treating superficial pyoderma? what additional treatment will you use?
3 weeks - must treat 1 week beyond clinical resolution
may use sole topical therapy for very focal lesions!!!!
otherwise, adjuvant topical therapy will speed up time to resolution
what is the minimum treatment duration for systemic antibiotics when treating deep pyoderma? what additional treatment will you use?
6-12 weeks + - treat at least 2 weeks beyond clinical resolution!!
base your abx off of the antibiogram, may need to biopsy to confirm infectious agent
adjuvant topical therapy will speed up resolution of disease
what is affected in surface pyoderma?
infection of the stratum corneum
what is affected in superficial pyoderma?
infection of the superficial interfollicular and/or follicular epithelium
what is affected in deep pyoderma?
infection of the dermis, subcutis, and/or deep soft tissue
what are some examples of underlying causes that lead to the development of pyoderma?
parasites, allergies, immune-mediated condition, neoplasia, microbial infection, & endocrine problem
what is the minimum database for dermatological diagnostics?
flea combing, skin scrapings, impression cytology, claw fold cytology, ear swabs, woods lamp/DTM, & +/- acaricidal mite treatment trial
are bacteria more likely to be resistant to antiseptics or antibiotics?
antibiotics! this is why antiseptics used as topical treatment is indicated for surface pyoderma treatment!!!
what are the standard go to ingredients in your topical drugs for treating surface pyoderma?
chlorhexidine, triz EDTA, & benzoyl peroxide
T/F: it is common to see moist exudation causing pruritus in dogs with hot spots which is an example of surface pyoderma
true
what is the name of this condition? what type of pyoderma is it associated with?
intertrigo - surface pyoderma
what is your mainstay treatment for surface pyoderma?
TOPICAL THERAPY
T/F: with superficial pyoderma, you may see pruritus & alopecia
true - it is +/-
what is the name of this condition? what type of pyoderma is it associated with?
mucocutaneous pyoderma - superficial pyoderma
what differentials are you considering in a case of surface pyoderma?
scabies mites
yeast infection - malassezia overgrowth
what kind of pyoderma has you considering what is pictured as differentials?
surface pyoderma
when do you want to reassess your patient with pyoderma while on recommended therapy?
2-4 weeks in depending on the severity of pyoderma
what dogs are commonly affected by hot spots?
dense coat breeds - st bernards, rotties, GSD, goldens, & labs
what time of year do we see a higher prevalence of hot spots in dogs?
warmer/humid weather
what is the pathogenesis of hot spots? what are they usually secondary to?
bacterial skin disease that results from self-trauma
secondary to pruritic skin disease such as fleas, parasites, allergic skin disease, & otitis or painful conditions such as OA, anal sac impaction, or trauma
what is the lesion distribution of hot spots?
caudodorsal rump, tail base, lateral thighs, cheeks, or neck
what are the clinical signs of a hot spot?
rapidly developing, pruritic/painful well-circumscribed, alopecic, eroded, excoriated erythematous patch +/- slightly raised plaque
surface oozing with adherent exudate & mats of hair - may see papules/pustules at the periphery of lesions
what are your main differentials for a dog with hot spots?
folliculitis - bacterial, demodicosis, or dermatophytosis
pyotraumatic folliculitis
sweat gland adenocarcinoma for lesions that aren’t responsive to therapy
what is seen on cytology taken from a hot spot?
suppurative inflammation with mixed bacteria
how are hot spots diagnosed?
acute history, clinical signs, & exclusions of the other differentials
clipping - diagnostic & therapeutic attributes
when are antibiotics indicated for treating a hot spot in a dog?
if papules/pustules are a feature indicating combo of surface & superficial pyoderma - appropriate b-lactam abx at correct dose for 3-4 weeks (1-2 weeks beyond clinical resolution)
what drug may be used instead of glucocorticoids for preventing self trauma in a dog with a hot spot?
oclacitnib - short course for 3-10 days
why use glucocorticoids for a dog with hot spots?
stop self trauma - use a topical preparation without alcohol or pred at 0.5-1.0mg/kg PO every 24 hours for 3-10 days
what is the treatment used for hot spots?
clip & clean affected area
topical therapies that don’t have alcohol!!!!!! peroxide, chlorohex, etc is okay & avoid occlusive ointments because it will keep the lesion moist
mechanical barrier - t-shirt or ecollar
appropriate flea control & treatments for any other potential underlying cause
+/- : systemic abx, glucocorticoids/oclacitnib
what is intertrigo?
skin fold pyoderma
what is the pathogenesis of intertrigo?
anatomical defect in which opposing frictional folds of skin result in a warm & moist environment favoring bacterial & yeast overgrowth & excessive sebum accumulation on the epidermal surface
seen in animals with natural body folds & acquired (obesity)
what animals are predisposed to intertrigo of the facial/nasal folds?
bracycephalic breeds
what animals are predisposed to intertrigo of the lip folds?
bracycephalic & dolichocephalic breeds
what animals are predisposed to intertrigo of the body folds including the axilla, inguinal area, truncal, & limb folds?
sharpei, hounds, spaniels, bull dogs, pugs, & certain terriers
what animals are predisposed to intertrigo of the tail folds?
corkscrew tail dogs - english bull dogs & pugs
what animals are predisposed to intertrigo of the vulvar fold?
dogs with recessed/poorly developed vulvas or obese dogs
what are the clinical signs seen with intertrigo?
stinky stinky stinky
pain, pruritus, erythema with moist surface exudates, & erosions from moist macerations
what are your main differentials for intertrigo?
folliculitis - dermatophytosis, demodicosis, or bacterial
malassezia dermatitis
urine scald
what is seen on cytology taken from a lesion of intertrigo?
mixed bacterial population +/- yeast +/- leukocytes
how is intertrigo diagnosed?
history, clinical signs, & exclusion of other differentials
cytology, oral exam, & cystocentesis UA to exclude ascending UTI
what therapy is used to treat intertrigo?
possibly clip & clean
topical therapy without alcohol - more frequent use & then taper to a maintenance frequency of administration
weight correction or corrective surgery
what is bacterial overgrowth syndrome?
newly recognized clinical pruritic syndrome of bacterial overgrowth on the skin surface (not hair follicle) without any typical lesions of pyoderma (papules, pustules, epidermal collarettes, crusts, exudation), but responds remarkably to antibiotic treatments
is bacterial overgrowth syndrome a true pyoderma? why?
no - it is not pyogenic
what are the typical distributions of bacterial overgrowth syndrome?
predominantly ventral trunk & occasionally otic canal
what lesions are associated with bacterial overgrowth syndrome?
erythema, oily seborrhea, hyperpigmentation, excoriation, lichenification, & ceruminous otitis
what are your main differentials for bacterial overgrowth syndrome?
intertrigo
malassezia dermatitis - may be concurrent
allergic skin disease - may be concurrent
what treatment is indicated for bacterial overgrowth syndrome?
topical therapy - antibacterial products
systemic abx - most cases require them, prescribed in a manner similar to superficial pyoderma
any treatments needed for any underlying diseases/conditions
what are some other names of impetigo?
puppy pyoderma or superficial pustular dermatitis
what is impetigo?
subcorneal skin infection not associated with the hair follicle
what agent is most commonly associated with impetigo?
staphylococcal bacteria
what animals do we most commonly see with impetigo? why?
young, prepubescent dogs
may be idiopathic, or it occurs secondary to poor husbandry, nutrition, endoparasitism, ectoparasitism, urine scald, or fecal debris
what is the typical lesion distribution of impetigo?
glabrous (non-haired) skin most often restricted to the axillae & inguinal areas
is impetigo a painful or pruritic condition?
nope
what lesions are seen in animals with impetigo?
interfollicular lesions that ARE NOT folliculitis - creamy, fragile pustules/crusted papules, & epidermal collarettes not oriented around hairs/hair follicles that are usually partially bilaterally symmetrical
what are the main differentials for impetigo?
folliculitis - bacterial, demodicosis, & dermatophytosis
sarcoptic mange
pemphigus foliaceus
how is impetigo diagnosed?
history of the animal, clinical signs, & exclusions of other differentials
cytology - suppurative inflammation with cocci
T/F: topicals alone are beneficial for treating impetigo
true
how is impetigo treated?
topical therapy
systemic antibiotics for at least 3 weeks if the patient isn’t responding to sole topical therapy
what is the most common clinical presentation of pyoderma in the dog that has no age or sex predispositions?
superficial bacterial folliculitis
T/F: breed predilections for superficial bacterial folliculitis parallel those predisposed to underlying diseases & conditions
true
what is the agent involved in superficial bacterial folliculitis until proven otherwise?
s. pseudintermedius
what is the pathogenesis of superficial bacterial folliculitis?
infection begins in the follicular ostia & spreads peripherally under the stratum corneum to other nearby follicles - infection tends to be secondary to other diseases
if left untreated or treated inappropriately, it may progress down the follicle leading to follicular rupture (furunculosis/deep pyoderma)
what are the most frequently encountered underlying diseases & conditions seen that cause superficial bacterial pyoderma?
DEMODICOSIS!!!!!!
pruritic/inflammatory/allergic skin disease, endocrinopathies (including iatrogenic hyperadrenocorticism), cornification defects, follicular dysplasias, nutritional abnormalities, & immune dysfunction
primary idiopathic superficial bacterial folliculitis may be seen in what animals?
short-coated adult dogs
superficial bacterial folliculitis is often mistaken for what in short-coated adult dogs?
hives - example is the boxer
T/F: because superficial bacterial folliculitis is so common in the dog, it is okay to perform an appropriate antibiotic treatment trial when in doubt
true
T/F: superficial bacterial folliculitis & malassezia dermatitis may coexist in a dog
true
what is the typical lesion distribution of superficial bacterial folliculitis?
axillary, inguinal, trunk, proximal limbs, interdigital webs
may generalize but spares the head
what is your main differential for superficial bacterial folliculitis?
folliculitis - demodicosis & dermatophytosis!!!!!
how can glucocorticoids cause misdiagnosis of superficial bacterial folliculitis?
glucocorticoids may lessen visible inflammation & development of typical lesions causing you to miss it
what lesions are seen in superficial bacterial folliculitis?
since pustules are transient, erythematous papules with or without crusting is the lesion most commonly seen
fragile, transient pustules with erythematous halo centered around the hair follicle leading to -> crusted papules -> epidermal collarettes -> alopecia -> hyperpigmentation
what type of alopecia is seen in animals with superficial bacterial folliculitis?
moth eaten alopecia in short-coated dog breeds
subtle alopecia/coat thinning/shedding in long-coated dog breeds
how is superficial bacterial folliculitis & superficial spreading pyoderma diagnosed?
history/clinical signs/exclusion of other differentials
cytology - cocci, activated neutrophils, +/- eosinophils
skin scrapes to exclude demodicosis
culture if not responding to empiric therapy
DTM for cats with folliculitis
why should you avoid using glucocorticoids when treating superficial bacterial folliculitis?
you can’t assess the influence of abx on pruritus in the face of steroids because they may reduce the inflammatory signs of pyoderma making you think it is resolved
what therapy is indicated for treating superficial bacterial folliculitis & superficial spreading pyoderma?
topical therapies
systemic abx - required for most cases, appropriate b-lactams for at least 3-4 weeks (at least 1-2 weeks beyond clinical resolution)
what is superficial spreading pyoderma similar to as far as clinical presentation is concerned? what animals do we commonly see it in?
superficial bacterial folliculitis
long-coated dog breeds - shetland sheep dogs
what is the typical lesion distribution of superficial spreading pyoderma?
truncal distribution especially in axilla & groin
what lesions are seen in superficial spreading pyoderma?
multiple, expanding, & coalescing epidermal collarettes with central erythema, crusting, or hyperpigmentation
what are the main differentials for superficial spreading pyoderma?
folliculitis - bacterial, demodicosis, & dermatophytosis
autoimmune dermatosis - pemphigus foliaceus & erythema multiforme
what is another name for superficial spreading pyoderma?
exfoliative superficial pyoderma
what animals are commonly affected by mucocutaneous pyoderma?
GSD & crosses of any age/sex - usually idiopathic without an underlying cause present
what is mucocutaneous pyoderma?
bacterial infection limited to the skin bordering the mucus membranes
what is the classic distribution of lesions from mucocutaneous pyoderma?
symmetric lesions along lip margins with increasing severity towards the commissures
rare to see signs along other mucocutaneous junctions
whats lesions are seen with mucocutaneous pyoderma?
erythema, swelling, exudation, adherent crusting, matting, erosions, ulcers, fissures, & depigmentation
pain & pruritus!!!!
how is mucocutaneous pyoderma diagnosed?
history, clinical signs, & exclusion of other differentials
cytology - cocci, rods, malassezia yeast, leukocytes
what is seen on a biopsy of a lesion of mucocutaneous pyoderma?
superficial crusting & erosions, epidermal hyperplasia, intraepidermal pustules with a lichenoid band at the dermoepidermal junction
how is mucocutaneous pyoderma treated?
topical therapy
systemic abx - b-lactams for 4-5 weeks
feline superficial pyoderma is clinically indistinguishable from what other skin condition?
dermatophytosis
what is the most commonly affected location of the body in cats with superficial pyoderma?
the face
what lesions are seen in cats with superficial pyoderma?
indolent ulcers & eosinophilic plaques (manifestations of allergic skin disease) are commonly infected with bacteria & usually improve with systemic abx therapy
what is the difference in regards to lesion distribution when it comes to superficial pyoderma in dogs & cats?
cats have a different distribution pattern & mimics many feline hypersensitivities
what is the common lesion distribution of feline superficial pyoderma?
cervicofacial, pinnae, ventral abdomen, trunk, flank, limbs
what lesions are seen in cats with superficial pyoderma?
erythema, papules (miliary dermatitis), plaques, scale, crusts, alopecia, erosions, ulcers, exudation, & swelling
pruritus is usually present
how is feline superficial dermatitis diagnosed?
history, clinical signs, & exclusion of other ddx
fungal culture/DTM to rule out dermatophytes
what antibiotics are commonly used for feline superficial pyoderma?
amoxi/clav, cefovecin, & TMS
what therapy is indicated for treating feline superficial pyoderma?
topical therapies when & if possible for focal lesions
systemic abx for 3-4 weeks
what lesions are typically seen in surface pyoderma?
erythema, surface exudates, erosions, excoriation, & slightly raised plaques
what lesions are typically seen in superficial pyoderma?
macule, papule, pustule, epidermal collarette, & crusts
a puppy comes in, & you see this lesion in their inguinal area - what do you suspect?
puppy pyoderma - impetigo
what are you big three differentials that should be considered for a patient with superficial pyoderma/folliculitis?
superficial bacterial pyoderma - most common cause of folliculitis in dogs
dermatophytosis - most common cause of folliculitis in cats
demodicosis
what lesions are seen with deep pyoderma?
gelatinous skin, devitalized skin, necrosis, pain, sloughing, edema, & cellulitis
what are some indications you should get a culture from an animal with deep pyoderma?
deep pyoderma - nodules or draining tracts are present
rods are present on cytology of skin & ears (otitis media)
what are some indications you should get a culture for an animal with superficial pyoderma?
empirical therapy isn’t working
lesions are unresolved with adequate treatment
new lesions are developing while on treatment
patient has recurrent pyoderma
