Traumatic Dermatitis Superficial And Deep Folliculitis Furunculosis Pododermatitis Notes

1. Skin diseases – Pyoderma, Pyotraumatic dermatitis, Superficial and Deep Folliculitis, Furunculosis, Pododermatitis

PYODERMA

Pyoderma = Pyogenic infection of the skin – generally bacterial but can involve fungi (opportunists)

• Primary Pyoderma – Skin infection what doesn’t reoccur after treatment

• Secondary Pyoderma – More common; Assoc. with persistant underlying problems that alter the skins resistance to infection. Usually reoccurs until primary condition is corrected

Causal Agents

• Staph. Intermedius (Also Staph. Schleiferi)

• Pseudomonas sp., Proteus sp and E-coli – In chronic, reoccurant or deep pyodermas (as 2⁰ invaders)

• Bacteroides spp, Fusobacterium spp., Clostridium spp. – In deep pyodermas

1. Surface Pyoderma

Pyotraumatic Dermatitis = Acute moist dermatitis or “hot spot”

Etiology

• Self trauma to the skin due to an underlying pruritic pr painful process focal surface pyoderma.

• Underlying conditions = Allergic skin diseases, Ectoparasites, Otitis Externa, Environmental causes, Anal Sac issues, Musculoskeletal disorders

• Most common cause is flea allergy dermatitis

Clinical Signs

• Single, alopecic lesion that is well circumscribed, erythematous, thickened and erosive; there is a thin film of exudate on top.

• Lesion devps after licking/chewing and can develop within hours of trauma!

Diagnosis:

History of self-trauma, acute onset, rapid development of the lesion, typical appearance on Physical exam

Treatment:

Topical therapy

• Clip long hairs, Cleanse the area (chlorhexidine)

• Dry the lesion and apply topical antibiotic/corticosteroid cream (e.g. panalog cream)

Systemic therapy

• Corticosteroids: if the lesion is painful and pruritic

• Systemic antibiotics – min. 3 weeks + 1 week after disappearance of clinical signs

Skin fold Pyoderma - Intertrigo

Etiology:

• Deep skin folds - Skin rubs against itself) irritation and trauma bacterial colonisation of the skin surface pyoderma

• Skin folds create most dark warm anaerobic conditions for bacteria to flourish. Folds retains skin secretions and skin cells promoting bacterial or yeast growth

• Staph. intermedius and Malassezia pachydermatis - most common

Clinical signs:

• Inflammation and mild exudation of the skin fold; malodorous.

• Best identified by widening of the skin fold

• Lip, Facial, Vulvar, Tail, Obesity fold, or Generalized

Treatment:

• Cleanse, disinfect and dry

• Bacteria only 2x daily with benzoyl peroxide containing gel

• Yeast +/- Bacteria 2X daily miconazole and chlorhexidine containing preparation

• In the case of sever inflammatory response 2-3days, 2X dailt panalog cream

• Preventive therapy: surgical correction by removal of the skin fold

2. Superficial pyoderma

• = Bacterial invasion of the epidermis

• 2 manifestations:

  • infection of the stratum corneum and pustule formation = Impetigo or puppy pyoderma

  • infection of the hair follicle (folliculitis)

• Staph. Intermedius is the most common pathogen

Impetigo

Etiology:

• Young dogs before puberty

• Contributing factors - Poor nutrition, poor environment, ecto or endoparasite infection

Clinical signs:

• Pustules in the inguinal and ventral abdomen regions that DO NOT involve the hair follicles

• When pustules rupture yellow-brownish crust forms

• Usually non-pruritic

• Usually an incidental finding during exam of newly acquired puppies

Diagnosis

• History, examination

• Cytology: stained contents of intact pustules show neutrophils and cocci

• Skin scraping to identify ectoparasites

• Bacterial culture, Skin biopsy, fecal flotatation (intestinal parasites)

Treatment

• Bathing the dog 2X week with a benzoyl-peroxide shampoo

• Systemic antibiotics are rarely required

Superficial folliculitis

Etiology:

• Primary folliculitis - bacterial infection of Staph intermedius (mostly) generally from trauma to skin

• Secondary folliculitis: more common; folliculitis is due to an underlying problem that alters the skin’s resistance to infection – reoccurrence until underlying issue is resloved

Clinical signs – Initially appears similar to impetigo

• Papules and pustules of the inguinal and ventral abdomen regions that may extend to the axillary and ventrolateral thorax

• Pustules are oriented around the hair follicle; base of pustule often erythematous; pruritis common

• If trunk of body is affected hair coat has a “moth-eaten” appearance

Diagnosis

• As for impetigo Fungal culture may also help

Treatment

As in impetigo (shampoo 2X weekly)

Systemic antibiotics - min 21 days and 7days after signs are gone

3. Deep pyoderma

= bacterial skin infection extending beyond the epidermis, into the dermis and occasionally the SC tissue

Deep folliculitis and furunculosis: most common form of a deep pyoderma

Pathogenesis:

Superficial folliculitis extension into the hair follicle Deep folliculitis destruction of the hair follicle release of bacteria, follicular keratins, follicle debris into surrounding dermis (SC) Deep folliculitis

• Bacteria can produce bacteraemia/septicaemia and the release of the hair shaft from the follicle creates a FB reaction = pyogranulomatous inflammatory reaction in the dermis

Etiology

• Staph intermedius is most common

• Secondary invading bacteria: Proteus spp., Pseudomonas spp., E. coli (contrary to superficial pyoderma)

• Rarely a primary disease - Often associated with another underlying medical condition/disease

Clinical Signs

• Earliest signs superficial pyoderma/folliculitis

With deep folliculitis and furunculosis:

• Papules and pustules are larger and nodular on palpation

• Exudation and crust formation. Ulcers and drainage tracts may devp.

• Haemorrhagic bullae possible

• Inguinal, ventral abdomen, axillary...

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