Skin infections Flashcards
(34 cards)
Most common bact and most common yeast on animal skin?
Staphylococcus pseudintermedius
Malassezia pachydermatis
Possible primary reasons for skin infections. (4)
Hypersensitivity disorders (atopic dermatitis, food allergy, flea bite hypersensitivity)
Endocrine diseases (hypothyroidism, hyperadrenocortitsism, hyperestrogenism in dogs)
Parasites (fleas, demodicosis, sarcoptic mites in dogs)
Other skins diseases (follicular dysplasias, autoimmune and immune mediated diseases, keratinisation defects)
Bacterial skin infections are divided by location: (3)
1) surface pyoderma
2) superficial pyoderma (bacterial folliculitis)
3) deep pyoderma
Surface pyodermas: (4)
1) Impetigo
2) Intertrigo
3) Mucocutaneous pyoderma
4) Pyotraumatic dermatitis (“hot spot”)
Deep bacterial infections: (6)
1) Acral lick dermatitis
2) Bacterial furunculosis
3) Callus furunculosis
4) Canine acne
5) Pododermatitis/podofurunculosis
6) Post-grooming furunculosis
Describe surface pyoderma: Impetigo
Affects only puppies.
Non follicular pustules, papules, epidermal collarettes, crusts on sparsely haired skin. Non pruritic.
Predisposed by malnutrition, wet/dirty environment.
Differentials: parasites (demodicosis, sarcoptosis), dermatophytosis, bacterial folliculitis).
Diagnosed by cytology: neutrophils and bacteria.
Treatment: topical antiseptic agents. NOT antibiotics.
Describe surface pyoderma: Intertigo
“fold dermatitis”
Nose fold, lip fold, tail fold, vulva fold. Breed predisposition.
Exudation, erythema, moisture in folds.
Ddx: malassezia dermatitis
Diagnosed by cytology.
Tx: topical antiseptic agents like chlorhexidine, if not responding then course of topical antibiotics, maybe consider topical steroids.
Also can consider surgery to reduce the folds.
Describe surface pyoderma: Mucocutaneous pyoderma.
Inflammation around eyes, nose, lips of dogs.
Erythema, crusts, depigmentation, edema, sometimes progresses to fissures.
Might be pruritic or painful.
Ddx: intertrigo, autoimmune diseases (pemphigus erythematosus, mucocutaneous pemphigus, skin lupus), epitheliotropic lymphoma.
Diagnosing - cytology!
Treatment - antiseptics, on more severe cases topical antibiotics, sometimes systemic antibiotics (high dose, 3 weeks course, for at least 1 week after resolution).
Prevention with cleaning (antiseptics).
Describe surface pyoderma: Pyotraumatic dermatitis.
„hot spot“
Quickly progressive superficial exudative dermatitis in dogs. Pruritic and painful.
Primary reason pain/pruritus/microtraumas/moisture (parasites + swimming).
Diagnosing - clinical signs, cytology.
Treatment - clipping (sedation might be needed).
Topical antiseptics, antipruritic drugs, more severe cases need topical antibiotics + systemic and topical glucocorticosteroids for pain and inflammation.
In case of satelite lesions - systemic antibiotics!
Antiseptic compounds for skin. (3)
Shampoos (2-4% chlorhexidine) over 1-3 days.
Contact time is important!
* Wipes, solutions, gels, mousse formulas
hypochlorous acid (HOCl) e.g. Vetericyn
Other antiseptics like chlorxylenol 2%, peptide AMP 2041
Describe the 2 most common Superficial pyodermas.
Bacterial folliculitis, bacterial pyoderma
Papules, pustules, crusts, alopecia, scaling, epidermal colarettes, hyperpigmentation, lichenification.
Might be highly pruritic.
Common flare factor for allergies, secondary to parasites, endocrine diseases etc. Recurrent pyodermas are common sign of hypersensitivites in dogs!
Diagnosing - cytology!
Treatment - treating primary diseases, topical antiseptics are first-line tx, more severe cases systemic antibiotics empirically. High dose, course at least 3 weeks.
If you see cocci, they’re likely Staph. pseudintermedius and you can try empirical AB first.
NB If rods seen or not responding - culture and sensitivity!
Multifocal alopecia in short coated dogs
(moth-eaten appearance)
Treatment of superficial pyodermas:
(aka bacterial folliculitis)
tx for at least 3 weeks.
Treat underlying disease + TOPICAL tx which is skin antiseptics/shampoos (2-4% chlorhexidine) over 1-3 days. NB Contact time!
Systemic treatment for superfiical pyodermas (if more severe and not responding to topicals):
In these cases, most likely agent is Staphylococcus pseudintermedius: use empiric treatment initially. Requires Higher doses, at least 3 weeks course!
But NB Culture and sensitivity if you see rod shaped bacteria on cytology or if not responding to treatment! Then you wanna switch to a more specific AB.
Skin infection is ALWAYS what?
secondary!
Describe Deep pyoderma: furunculosis.
Is a Complicated infection: progressed folliculitis + foreign body reaction in the skin (breaking of follicles).
Often multifactorial and frustrating!
Cytology might reveal fewer bacteria, but eosinophils (!), macrophages might be seen in addition to neutrophils.
Before systemic treatment culture and sensitivity should be done! 60% are Staphylococcus pseudintermedius, which need long AB courses 4-12 weeks.
Culture from draining tracts and fistulas, FNA, biopsy.
deep pyoderma means its in the dermis
eosinophils are not often seen in dog skin so is a good indicator of furunculosis with foreign body reaction
Describe Deep pyoderma: acral lick dermatitis in dogs.
Licking of the dorsal carpus, dorsolateral metatarsal regions etc.
Alopecia, plaques, erythema, exudate, fistulas.
Primary reasons: hypersensitivities, pain, endocrine diseases.
Diagnosing - clinical picture, cytology.
Treatment - antibiotics based on culture + treating the primary disease.
Use an Elisabeth collar in conjunction with other tx.
acral = referring to the highest or topmost portion of the limbs (extremities)
Describe deep pyoderma: Bacterial furunculosis.
Thick crusts, alopecia, fistulas. Might be pruritic or painful.
What is primary disease? There’s something causing these.
Diagnosing - cytology.
Treatment - antibiotics based on culture + treating the primary disease.
Describe deep pyoderma: Callus pyoderma.
Callus often forms on pressure points: elbows, hocks, sternum.
In case of secondary infection - edema, fistulas, ulcers, pruritus.
Treatment: antibiotics based on culture + treating the primary disease.
Use Soft bedding, wound management, some use joint pads.
Describe deep pyoderma: Canine acne.
Papules, pustules, bullas, fistulas on muzzle and chin.
Large breed, short haired dog in puberty are in risk.
Might be related to rubbing/trauma.
Diagnosing - cytology.
Treatment - in mild cases, topical antibiotics.
Systemic antibiotics based on culture + treating the primary disease.
Describe deep pyoderma: Podofurunculosis.
Interdigital erythema, pulstules, nodules, fistulas, alopecia, edema.
Might be pruritic or painful - licking.
Large short coated breeds are iat risk.
What is your primary disease? There’s something causing this.
Diagnosing - cytology.
Treatment - antibiotics based on culture + treating the primary disease (pain medication, weight management, allergy treatment).
Even Cyclosporine can be considered in some cases.
Can lead to false paw pad formation.
Podofurunculosis, interdigital cysts.
Primary diseases? (+ obese dogs, orthopedic problems, weight bearing, P4-P5 !!)
Can lead to false paw pad formation, “valeantura”.
Describe deep pyoderma: Post-grooming furunculosis.
Rare, but serious! 24-48 h after grooming in a salon.
Erythema, edema, erosions, hemorrhagic bullaes, exudation body and back area.
Might be febrile, depressed, develop into sepsis.
Trauma + infected shampoo
Short coated breed predisposed.
Treatment:
Culture and sensitivity. If rods on cytology then start fluoroquinolones (e.g. ciprofloxacin, enrofloxacin), if cocci, then cephalosporins while you await the results.
Pain medication, clipping in sedation, intravenous fluids, etc.
Describe Antimicrobial resistency main bacterial species. (3)
MRSP (methicillin resistant Staphylococcus pseudintermedius). Humans carry MRSA (S.aureus).
NO DIFFERENTIATION CLINICALLY. NOT MORE VIRULENT. CULTURE TO TELL APART!
Multiresistant E.Coli ja Pseudomonas aeruginosa.
What would be the best AB option for superficial pyoderma (bacterial folliculitis) (S.pseudintermedius)?
Use category D: Prudence Abs first e.g. trim+sulfa
If needed, move to category C: Caution e.g. amoxicillin+clavulanate, clindamycin, cephalexin (1st gen. cephalosporin)
Use BSAVA guidelines and EMA categorisation of AB guidelines.
