chapter
Symptom Checker^6
(Lesional and Regional
Dermatoses)
DEFINITION/OVERVIEW
Characteristics and patterns of lesions can often help narrow the differential list when
examining a patient.
The bulleted lists below are included as a tool to aid in formulating a differential list.
It is impossible to make such a list all inclusive and completely accurate: many
diseases/conditions have overlapping clinical signs.
This chapter is intended to function as a preliminary guideline, a “symptom checker,”
for some of the more common dermatoses.
PATCHY ALOPECIA
Demodicosis: often accompanied with hyperpigmentation, comedones, erythema,
and secondary folliculitis (Figures 6.1, 6.2).
Dermatophytosis: associated with scaling and folliculitis.
Staphylococcal folliculitis: papules, pustules, crusts, epidermal collarettes, hyperpig-
mented macules, individual or large coalescing and “spreading” (Figure 6.3).
Injection reaction: may be induration and/or atrophy at the site, often associated with
repositol corticosteroid injection or routine vaccinations (Figure 6.4).
Vaccine-induced vasculitis: lesion may or may not be associated with erythema, often
rabies vaccine induced, may be observed 2–3 months after injection (Figure 6.5).
Alopecia areata: noninflammatory complete focal alopecia, immune mediated, lym-
phocyte attack on hair bulb (Figure 6.6).
Localized scleroderma: rare, shiny, smooth sclerotic patch (Figure 6.7).
Sebaceous adenitis (short-coated breeds): annular to polycyclic areas, often associated
with scaling (Figure 6.8).
Anagen defluxion: sudden onset, stressful event or medication reaction, noninflam-
matory.
Bowenoidin situcarcinoma (BISC): primarily seen in cats, possibly secondary to
papillomavirus infection – pigmented scaling patches, often the head and pinnae
(Figure 6.9).Blackwell’s Five-Minute Veterinary Consult Clinical Companion: Small Animal Dermatology, Third Edition.
Karen Helton Rhodes and Alexander H. Werner.
©2018 John Wiley & Sons, Inc. Published 2018 by John Wiley & Sons, Inc.
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