Pyoderma is almost always….
Folliculitis
Top 3 causes of folliculitis
Pyoderma
Demodex
Ringworm
What species is bacterial folliculitis and furunculosis common?
Canine
What species is cellulitis and abscesses most common?
Feline
What is folliculitis?
Inflammation of hair follicle
Inflammation of superficial epidermis
Note: cats do not get true folliculitis
Why do pyodermas develop?
Usually secondary to an underlying disease process
Think: allergies or endocrine
Resident skin bacteria
Staphylococcus sp.
Micrococcus sp.
Streptococcus sp.
Acinetobacter sp.
Transient skin organisms
Gram (-)
E. coli
Proteus mirabilis
Pseudomonas sp.
Transient skin organisms
Gram (+)
Staph sp.
Corynebacterium sp.
Streptococcus sp.
Transient skin organisms
What do they do?
May colonize abnormal skin surfaces
Generally do not penetrate and cause infection directly
May become secondary invaders to Staph (already infected skin; especially deep infections)
Pathogenic coagulase positive Staphylococci
Types
Staph. pseudointermedius (most common)
Staph. schleiferi (second most common)
Rarely Staph. aureus
Pathogenic coagulase positive Staphylococci
Resistance
Penicillin
What is MRSP?
Methicillin-resistant Staph. pseudointermedius
Natural barrier to infection
Physical
Stratum corneum
Hair
Has normal flora
Natural barrier to infection
Physiologic
Skin cell turnover rate
Sebaceous gland/Sebum (has antimicrobial properties)
Natural barrier to infection
Immunologic
Langerhans’ cells (antigen presenting cells; helps prevent infection)
Lymphocytes
Sweat
What does pyoderma do to natural barrier functions?
Alters it:
Micro-environment of skin (skin folds)
Suppresses immune system (endocrine, steroids)
Pathogenic bacteria mechanism
Adhere to skin, colonize, and infect abnormal skin
Surface pyoderma
What is it?
Bacterial overgrowth
Skin erosions (surface irritation or trauma) with secondary adherence and colonization of abnormal skin surface by coagulase positive Staph
No inflammation
NOT folliculitis
Skin fold dermatitis
Pathophyisology
Surface pyoderma
Anatomical defects create warm moist environment for bacterial adherence and colonization
Accumulation of tears, sebum, urine
Skin fold dermatitis
Clinical Sings
Surface pyoderma
Erythema Alopecia Exudation within skinfolds \+/- pruritic Odor
Skin fold dermatitis
Types
Surface pyoderma
Facial fold Lip fold Vulvar fold Tail fold Mammary fold Obesity fold
Skin fold dermatitis
Diagnosis
Surface pyoderma
History PE Scrape Surface cytology (tape, cotton swab, impression) Response to treatment
Skin fold dermatitis
Treatment (broad)
Surface pyoderma
Goal: keep folds dry
If deep lesions present may have to use antibiotics
Do NOT use steroids
Usually: shampoos, wipes, sprays, mousse, ointment
Skin fold dermatitis
Treatment: topical antibacteirals
Surface pyoderma
Chlorhexidine
Mupirocin ointment
Benzyl peroxide
Skin fold dermatitis
Treatment: Antifungal
If cytology reveals yeast
Combination products with antibacterials: MalaKet, MiconaHexTriz, etc.
Pyotraumatic dermatitis
What is it?
Surface pyoderma
Hotspot
Acute moist dermatitis
Pyotraumatic dermatitis
Signalment
Clinical Signs
Surface pyoderma
Thick coated, long haired Alopecia Erythema Exudation Ulceration Lesion well demarcated from normal skin Pruritus Pain
Pyotraumatic dermatitis
Pathophysiology
Surface pyoderma
Self trauma
Rule out underlying causes (fleas, allergies, ectoparasites)
Pyotraumatic dermatitis
DfDx
Demodex
Pyotraumatic dermatitis
Diagnosis
PE
Skin scraping (rule out demodex)
Cytology
Response to treatment
Note: lesions around face are usually deep lesions and not hotspots
Pyotraumatic dermatitis
Treatment (broad)
Treat underlying cause (ex. flea control)
Clip and clean
Pyotraumatic dermatitis
Treatment: Antibacterials
Usually topical
Only have to do systemic antibacterials for deep infections
Chlorhexidine (spray, wipes, shampoo, mousse)
Mupirocin ointment
Pyotraumatic dermatitis
Treatment: Antipruritics
Topical anesthesia (lidocaine, paramoxine)
Oral steroid
Cytopoint
Apoquel
Superficial pyoderma
What is it?
Infection restricted to under the stratum corneum or within the ostia of the hair follicles
Impetigo
What is it?
Superficial pyoderma
Puppy Pyoderma
Infection just beneath stratum corneum of the non-haired areas (axillae and inguinal region)
Impetigo
Underlying causes
Superficial pyoderma
Parasitism
Viral infections
Dirty environment
Poor nutrition
Impetigo
Clinical Signs
Superficial pyoderma
Papules, pustules, crusts, epidermal collarettes, crusted papules, hyperpigmented macules
Pruritus variable
Axillae and inguinal regions main affected areas
Impetigo
Signalment
Superficial pyoderma
Less than 1 year of age
Impetigo
Diagnosis
Superficial pyoderma
History, PE Epidermal collarettes! Skin scraping (rule out demodicosis) Cytology; neutrophils with cocci Response to treatment (if it does not respond to treatment think underlying food allergies)
Impetigo
DfDx
Demodicosis
Dermatopytosis
Impetigo
Treatment
Can be a self-limiting disease
Topical: chlorhexidine, mupirocin ointment
Systemic anitbiotics for 3 weeks
Folliculitis (KNOW)
What is it?
Superficial bacterial folliculitis typically referred to as pyoderma
Infection starts in ostia (enterance into hair follicle) and spreads outward under the stratum corneum
Folliculitis (KNOW)
Clinical Signs
Superficial pyoderma
Papules, pustules, crust!
Epidermal collarettes
Patchy alopecia (mouth-eaten)
+/- pruritus (irritation, usually secondary to underlying disease; allergies, ectoparasites)
Folliculitis (KNOW)
Cause
Superficial pyoderma
Usually secondary to underlying disease process
Think: allergies or endocrine
Papules and pustules think X until proven otherwise
Folliculitis
Folliculitis (KNOW)
Distribution of lesion
Superficial pyoderma
VENTRUM (chest, abdomen)
Axillae
Inguinal region
Focal, multifocal, or generalized
Usually spares legs and head
Folliculitis (KNOW)
If pruritus rsolves with antibiotics than…
True folliculitis and steroids are contraindicated
Do NOT give steroids until have a diagnosis
Folliculitis (KNOW)
Pathophysiology
Superficial pyoderma
Something has altered the natural barrier to infection
Frequently secondary to underlying cause (allergies or endocrine)
Folliculitis (KNOW)
Pruritic causes
Allergies (flea, food, atopy)
Parasites (scabies, chyeletiellosis)
Skin fold
Folliculitis (KNOW)
Nonpruritic causes
Parasites (demodex)
Endocrine (Hypothyroidism, Cushing’s)
Folliculitis (KNOW)
Other causes
Chronic steroid administration Immune dysfunction Malnutrition Environmental factors Frequent bathing High-humidity Poor grooming
Folliculitis (KNOW)
DfDx
Must rule out:
Demodicosis
Dermatophytosis
Others:
Sterile folliculitis (eosinophilic folliculitis)
Autoimmune (pemphigus foliaceus)
Folliculitis (KNOW)
Diagnosis
Pyoderma = clinical diagnosis
History and PE
Skin scrapings (rule out demodex)
Cytology: neutrophils with or without cocci (taken from intact pustules, crust, epidermal collorette)
Fungal culture; rule out dermatophytosis
Response to treatment (should respond to antibacterials)
Folliculitis (KNOW)
Treatment: avoid
Do NOT used steroids (or combination products with steroids)
Folliculitis (KNOW)
Treatment: Focal
Topical: chlorhexidine or mupirocin
2-3 weeks
Shampoos
Medicated wipes
Sprays
Mousse
Folliculitis (KNOW)
Treatment: Multifocal
Topical
+/- systemic antibiotics
Folliculitis (KNOW)
Treatment: Generalized
Systemic antibiotics
1-2 weeks beyond clinical resolution! (3-4 weeks total)
Avoid undertreatment; starting to see resistance
First Tier Class Antibiotics (KNOW)
When to use them
If no prior history of antibiotics used
OR
If previous empirical treatment was effective
Beta-lactam Antibiotics
Examples
First tier class antibiotics
Cephalexin (1st generation); best choice
Cefpodoxime (Simplicef) (3rd generation)
Cefovecin (Convenia) (3rd generation)
Amoxicillin with clavulante (Clavamox); high dose of 20 mg/kg q12 but should avoid using
Folliculitis
Reasons for treatment failure
Resistance Wrong diagnosis (demodex, dermatophytosis, autoimmune) Wrong antibiotic or wrong dose Too short of a course of antibiotics
Failure to identify underlying cause (allergy or endocrine)
Folliculitis (KNOW)
Culture?
Reconsider DfDx first
When there is no response to first tier or empirical treatment
Deep pyodermas
Cytology reveals mixed infection (rods and cocci)
Immunosuppression
Folliculitis (KNOW)
Culture interpretation
Make sure you have cultured staphylococcal organism, especially Staph. pseudintermedius or S. schleiferi
Resistance to oxacillin = resistance to methicillin = resistance to beta-lactam antibiotics = MRSP/MRSS
Second tier class antibiotics When to use
ONLY use based off of C/S results
Second tier class antibiotics Examples
Fluoroquinolones Clindamycin TMS Doxycycline Rifampin Amikacin Chloramphenicol
If focal try topical; if getting worse give systemic treatment
Must be on antibiotics for 3-4 weeks (must re-check)
Third tier class antibiotics When to use
Should not be used for ethical reasons!
Reserved for humans and treatment of MRSA
Third tier class antibiotics Examples
Linezolid
Vancomycin
Mucocutaneous pyoderma
What is it?
Superficial pyoderma affecting the lips and perioral skin
Usually staph infection
Mucocutaneous pyoderma
Clinical Signs
Swelling and erythema of lips, especially commissures
Crusting and fissuring may follow
Similar lesions may occur at nares, medial canthus, vulva, prepuce, anus
Hypopigmentation may be seen
Seen most commonly in GSD
Mucocutaneous pyoderma
Pathophyisology
Unknown!
Does not originate from lip folds
Mucocutaneous pyoderma
DfDx
Demodicosis
Autoimmune (discoid lupus erythematosus, pemphigus)
Lip fold dermatitis
Mucocutaneous pyoderma
Diagnosis
PE
Skin scraping
Cytology; bacteria and if not than maybe Lupus
Culture
Mucocutaneous pyoderma
Treatment
AVOID steroids
Topical antibacterials: mupirocin, chlorhexidine
Systemic antibiotics; 3-4 weeks
Look for underlying disease; allergies or endocrine
Deep pyoderma
What is it?
Deep infections of deeper regions of the hair follicle, dermis, and subcutis
Includes deep folliculitis/furunculosis and cellulitis
Less common than superficial pyoderma; can occur in conjunction with
Deep pyoderma Diagnostic approach (broad)
ALWAYS CULTURE
May be Staph or gram (-) bacteria (Pseudomonas)
Furunculosis
What is it?
Nodular dermatitis secondary to bacterial infection deep in a hair follicle (deep folliculitis) and subsequent rupture of that follicle (furunculosis)
Rare in cats!
Furunculosis
Pathophysiology-Causes
Pyodermas are secondary to an underlying disease! Starts superficial than moves deeper
Allergies (flea, food, atopy) Endocrine (hypothyroidism, Cushing's) Ectoparasites Inappropriate use of corticosteroids Inappropriate antibiotic therapy Poor nutrition Foregin body Immune dysfunction
Furunculosis
Pathophysiology-What occurs
Hair follicle ruptures (furunculosis) and releases bacteria, hair, and follicular keratin into the dermis that insights a pyogranulomatous inflammatory reaction
Bacteria present usually Staph. pseudintermedius
Can also be: Proteus, Pseudomonas, E. coli
Furunculosis
Clinical Signs
Papules Nodules Hemorrhagic bullae or vesicles Draining lesions Cellulitis Lymphadenopathy Systemic illness
Furunculosis
DfDx
Demodicosis Fungal infections Foreign body Sterile Neoplasia
Furunculosis
Diagnosis
History and PE Skin scraping (rule out demodex)
Cytology:
Pyogranulomatous inflammation
+/- cocci with or without rods
Culture and Sensitivity!
need a sterile punch biopsy; collect with sterile instruments and put in a red top with saline
Do NOT swab surface; not helpful
Furunculosis
Kinds
Canine acne
Nasal pyoderma
Interdigital pyoderma
Hot spot pyoderma/pyotraumatic folliculitis/furunculosis
Furunculosis
Treatment
Based on C&S results:
Systemic antibiotics: 6-12 weeks! 2 weeks past clinical remission
Look for underlyin gcuase of pyoderma (allergies? endocrine?)
Topical antibacterial shampoo (chlorhexidine)
Canine acne
Breeds
Furunculosis
Doberman
Great Dane
English bulldogs
Boxer
Canine acne
Location
Furunculosis
Chin
Muzzle
Canine acne
Cuase
Furunculosis
Trauma?
Genetics?
Puberty?
Canine acne
Treatment
Furunculosis
Topical or systemic antibiotics in more severe cases
Interdigital pyoderma
Furunculosis
Commonly seen in many disease processes: Allergic disease Parasitic disease (Demodex!) Infectious diseases (fungal) Endocrine diseases Sterile (rare) Foreign bodies (generally rare)
Interdigital pyoderma
Lesions
Furunculosis
Papules Nodules Vesicles Bullae Draining lesions
Hot spot pyoderma
AKA
Pyotraumatic folliculitis/furunculosis
Hot spot pyoderma
What causes this?
Scratching!
Secondary allergies can be the underlying cause
What disorder is caused by dog biting at themselves?
Pyotraumatic dermatitis
Hot spot pyoderma
Lesions
Plaque-like alopecia
“Satellite” papule lesions
Look at ears
Usually seen around face and neck