Page 1524 - Clinical Small Animal Internal Medicine

1462 Section 12 Skin and Ear Diseases

of skinfolds are predisposing factors for staphylococcal
VetBooks.ir intertrigo. The aforementioned factors result in surface
maceration of the stratum corneum and bacterial over-
growth, predominantly with staphylococci. Concurrent
Malassezia overgrowth is common, and gram‐negative
bacteria may also contribute. It is largely a condition in
dogs, particularly in the context of hypersensitivity, and
is rare in cats. Intertrigo is typically pruritic. Locations
affected include abdominal, inguinal, vulvar, lip, tail, and
facial folds, with the latter two locations overrepresented
in English bulldogs and pugs. Moist erythematous skin,
purulent exudate, and in advanced cases ulcerative der-
matitis are observed (Figures 166.2, 166.3, and 166.4).
Cytology of exudate obtained via surface impression
Figure 166.1 Acute moist dermatitis in a golden retriever dog smear confirms the presence of cocci and may also
with atopic dermatitis and superficial staphylococcal folliculitis.
involve yeast and rods. Neutrophils are variably present.
Topical antimicrobial and drying agents are indicated.
may be the inciting cause of the acute moist dermatitis.
This scenario is termed “pyotraumatic folliculitis.”
Patients may present on an emergency basis due to
rapid, severe progression. Lesions can be painful. Sedation
may be required prior to clipping of the coat for optimal
examination and initial topical treatment. A thorough
examination of the entire coat and obtaining a detailed
history are critical, as diagnosis and appropriate manage-
ment of the underlying pruritic disease are very impor-
tant, particularly in recurrent cases.
Initial treatment involves cleansing of the lesion
with an antimicrobial. A 2% aluminum acetate solution
(Domeboro® solution, Bayer) may be used as a topical
nonirritating drying and antimicrobial agent. At‐home
therapy involves daily application (1–3 times/day) of a
topical antimicrobial and/or drying agent; use of a topi-
cal anesthetic (e.g., pramoxine, lidocaine) or corticoster-
oid may be additionally beneficial. Limit daily topical Figure 166.2 Mildly erythematous and greasy Staphylococcus
and Malassezia nasal fold dermatitis with crusting staphylococcal
corticosteroid use to no more than one week to avoid folliculitis in a pug with atopic dermatitis.
cutaneous side‐effects, such as demodicosis, comedones,
cutaneous atrophy, and ulceration.
Application of an Elizabethan collar or breathable
physical barrier is recommended in the first 3–7 days of
treatment to prevent self‐trauma. Oclacitinib (Apoquel®,
Zoetis), lokivetmab (Cytopoint®, Zoetis), or systemic
corticosteroid treatment is often required to provide
rapid relief of pruritus, and, for severe presentations,
may be required for several days before topical therapy
is attempted at home. Concurrent systemic antimicro-
bial therapy is required for pyotraumatic folliculitis
(see also “Treatment of pyodermas” section below).
The patient should be rechecked in 7–14 days to assess
response to antimicrobial and antiinflammatory
therapies.

Intertrigo Figure 166.3 Dorsal interdigital moist erythema with Malassezia
Increased warmth and humidity of the environment, fric- and Staphylococcus overgrowth in a 5‐year‐old Rottweiler with
tion, and the protected cutaneous microenvironments atopic dermatitis.