Bacterial Skin Disease Flashcards
What is bumble foot? Which spp get this?
- S. aureus
- Birds and small furries
- usually associated with obesity/management problems
Is pyoderma ever primary?
No always 2*, opportunistic bacteria
- always ID and Tx underlying cause
What may predispose to 2* pyoderma?
- break in physcial skin barrier (trauma)
- loss of immunity
- ectoparasites, alleriges, cornification defects, neoplasia, alopecia
- endocrinopathy, metabolic/nutritional problems
What is exudative epidermitis in pigs known as? Pathogen?
- staph hyacus
- Greasy pig disease
Which bacteria are most commonly involved with pyoderma?
> Staph (G+) - s. pseudintermedius - may be other staphs too eg. hyicus in pigs > Strep (G+) > G- (esp deep pyoderma) - coliforms - pseudomonas - proteus
History signs of pyoderma?
- recurrent pyoderma
- previous response to Abx therapy
Clinical signs seen with pyoderma?
- papules
- pustules
- epidermal collarettes
- draining sinuses
Cytology findings of pyoderma?
- tape strip, impression smear stained
- need intracellular bacteria and inflammatory cells (presence of bacteria is not diagnositc)
Is C+S used to diagnose pyoderma?
- NO!!!
- used to ID organisms but not diagnose pyoderma
- search for underlying/triggering causes
Tx surface pyoderma?
- long term therapy
- surgical correction? skin folds
- ABx topical shampoo/cream
What are the 3 forms of pyoderma?
- Surface
- Microbial proliferation
- eg. Intertrigo (folds), mucocutaneous pyoderma
- eg. pyotraumatic dermatitis [painful!]
- bacterial overgrowth
- pruritis
> Superficial
- Impetigo (puppies)
- Folliculitis/supf. pyoderma
- very common
- pruritis
> Deep
- furunculosis
- acne (chin)
- bacterial granuloma
- painful
Ddx mucocutaneous pyoderma?
Lupus
- if responds to Abx then is pyoderma, if not is immune mediated
What is pyotraumatic dermatitis? What type of opyoderma is this?
- acute
- Painful
- but SURFACE pyoderma
- hot spot or acute moist dermatitis
- serlf trauma or bacterial invasion
-> disruption of stratum corneum - often large breeds eg. retriever
> underlying pruritic problem (FAD, anal sac irritation, otitis)
Tx pyotraumatic dermatitis hotspots?
- topical Abx
- anti-inflam depending on severity (topical/systemic GCs)
- treat underlying causes
What pathology is seen in similar dogs and appears similarly to pyotraumatic hot spots but is differnet? Tx?
- Pyotraumatic FOLLICULITIS and FURUNCULOSIS
- satellite lesions suggest haematogenous spread = dermis
- => deep pyoderma
- GC CONTRAINDICATED
What is inpetigo?
- pustules in interfollicular epidermis
- young dogs affected
- ventral abdomen common
- often responds to topical therapy alone
What pathogen is involved in 90% canine superficial pyoderma? Which level of dermis is afected?
Staph pseudintermedius
- mostly endogenous strains
> superficial portion of the hair follicle typically on ventral abdomen and trunk
What may affect clinical presentation of superficial pyoderma?
coat length
- short coat breeds may appear moth eaten (Ddx ringworm)
What lesions are seen with superficial pyoderma?
In this order…
- macule
- papule
- pustule (neutrophils invade) transient, rupture, usually only a few present (if lots of pustules think PEMPHIGUS)
- epidermal collarette (central hyperpigmentation)
- alopecia and pruritis
> combination of all these
Tx of DEEP pyoderma?
- serious, painful, lengthy
- 6-10 weeks
- discuss with owner at begninning
Which underlying causes of deep pyoderma are there?
- Demodecosis very common and easy to find, ALWAYS CHECK
- immune imbalances (breed specific)
Which pathogens are associated with deep pyoderma?
- Staph (60%)
- G- and anaerobes
> Bacterial culture ALWAYS INDICATED cf. superficial pyoderma where empirical tx for s. pseudoiontermedius is ok
Diagnosis of deep pyoderma based on..
- bacterial culture
- skin biopsy (NOT in formalin)
- cytology, skin scrapes, bloods, imaging for underlying cause
Lesions associated with deep pyoderma?
- heamorrhagic crusts
- draining tracts
- alopecia with no self-trauma
What presentation of deep pyoderma is seen on the face?
Acne under the chin
- dogs and cats
- chronic and young animals
Causes of deep pyoderma acne?
- Cats: demodecosis, dermatophytosis, FeLV, FIV, ALLERGIES
- Dogs: short haired breeds, underlying cuases
Tx of acne
Shampoos, topical creeams and systemic
What form of deep pyoderma is seen on the limbs?
Acral lick dermatitis
- large breed dogs
- chronic
- bacterial growth from >95% cases
- underlying joint disease, allergy, behavioural (boredom?)
Tx acral lick deep pyoderma?
- longterm ABx
- prevent trauma
Duration of treatment for superficial and deep pyoderma?
> superficial
- >3weeks or 1 week beyond complete clinical cure
deep
- >4-6 weeks or 2 weeks beyond complete clinical cure
until underlying trigger has been addressed
beware compliance
Why are biofilms a problem?
- bacteria producing them are resistant to ABx (even if appear susceptable to drugs in lab)
- no lab tests to detect biofilm
> G+ (staph and strep, enterococcus, actinomyces, corynebactera, bacillus)
> G- (serratia marcesens, pseudomonas aeruginosa especially, legionella, moraxella, E.coli/salmonella)
> multidrug resistnat strains too
Which species is C+S more often indicated?
Cats
- predators so multiple sources of drug ingestion and ^ likelihood of resistance
How may disease causing bacteria be distinguished from commensals on a smear?
- intracellular bacteria associated with inflammatory cells rather than free floating (planktonic)
Which pathogen can all strains form a biofilm?
pseudomonas
