Page 1525 - Clinical Small Animal Internal Medicine

166 Bacterial Pyodermas 1463

Superficial Bacterial Folliculitis
VetBooks.ir presentation of pyoderma and, as stated previously,
Superficial bacterial folliculitis is the most common
opportunistic S. pseudintermedius is the most common
etiologic agent. Infection of the hair follicle and epider-
mis produces characteristic follicular‐oriented papules,
pustules, and epidermal collarettes (Figure 166.5) pro-
gressing to crusts, “moth‐eaten” alopecia, and hyperpig-
mentation (Figures 166.6 and 166.7).
In short‐coated dogs, well‐demarcated areas of raised
hair resemble urticaria from afar. Papular crusting derma-
titis (i.e., miliary dermatitis) is most frequently observed
in cats. Distribution is dependent on cause, and pruritus is
variable.
Differential diagnoses for folliculitis include, but are
not limited to, dermatophytosis, demodicosis, pemphi-
Figure 166.4 Severe, purulent tail fold intertrigo with mixed gus foliaceus, and, in cats, hypersensitivity syndromes.
bacterial overgrowth and crusting staphylococcal superficial Systemic and topical treatment is indicated for patients
bacterial folliculitis in an English bulldog with atopic dermatitis.
Surgery was ultimately required for control of the dermatitis.

Surgical correction of redundant folds may be indicated
for severe, recalcitrant presentations.

Superficial Pyodermas
Impetigo
Impetigo, also referred to as “puppy pyoderma,” occurs
in puppies and juveniles less than 1 year old. It is typified
by subcorneal, often grossly large, pustules caused by
staphylococci, most commonly S. pseudintermedius. The
pustules do not necessarily involve the hair follicles and
are typically located in the axillary and inguinal areas.
The pustules progress to crusts and epidermal collar-
ettes. Patients are not typically pruritic nor painful. Figure 166.5 Epidermal collarettes with macular erythema and
Cytology of pustules reveals degenerated neutrophils hyperpigmentation on the abdomen of a terrier mix with
and intracellular cocci. superficial staphylococcal folliculitis, atopic dermatitis, and
Impetigo is often idiopathic in otherwise healthy pup- iatrogenic hypercortisolism.
pies. It may also occur in immunocompromised patients
suffering from parasitic or infectious diseases, or subop-
timal nutrition and housing conditions.
Impetigo is expected to self‐resolve in otherwise
healthy patients. Use of topical antimicrobial therapy
may hasten resolution and may be required for resolu-
tion in immunocompromised patients. Treatment
options include daily to alternate‐day shampoo treat-
ment with a nondrying, antimicrobial shampoo includ-
ing chlorhexidine or ethyl lactate. Alternatively, for focal
lesions, consider convenient antimicrobial wipes, sprays,
foams, and ointments/creams applied once or twice
daily. Continue topical therapies until lesion resolution.
For severe cases or cases that do not respond to topical
therapy, systemic antibiotics are indicated. Systemic Figure 166.6 Well‐circumscribed partial alopecia, crusting and
antimicrobial treatment should continue for one week moist erythematous skin of the periocular and perioral regions
past resolution of lesions. Resolution of lesions is due to superficial staphylococcal folliculitis in a 7‐year‐old
expected to occur within 14 days. domestic shorthair cat with atopic‐like dermatitis.