CHAPTER 6 SYMPTOM CHECKER (LESIONAL AND REGIONAL DERMATOSES) 67
NASAL PLANUM DERMATOSES
Discoid lupus erythematosus: primarily affects nasal area, depigmentation, exacer-
bated by sunlight, loss of cobblestone architecture.
Systemic lupus erythematosus: multisystemic disease; face, nose, mucocutaneous
junctions, generalized.
Pemphigus complex: immune-mediated skin disease, often more crusted than ulcer-
ative, variable depigmentation; footpad crusting common (Figures 6.108, 6.109).
Bullous pemphigoid: often associated with crusting and depigmentation; mucocuta-
neous junction common.
Nasal solar dermatitis: starts at poorly pigmented junction of nasal planum and bridge
of the nose, heavy sunlight exposure; differentiated from discoid lupus erythematosus
by lack of involvement of the nasal planum (Figure 6.110).Contact dermatitis: not common; rubber dish; rare ulceration, erythema and depig-
mentation of the anterior nasal planum and lips (Figure 6.111).
Dermatomyositis: nasal, facial, extremities; scarring depigmentation/ulceration;
polymyositis and megaesophagus may be seen.
Uveodermatologic syndrome: uveitis; depigmentation, ulceration nose, lips, eyelids
(Figure 6.112).
Nasal arteritis: profusely bleeding, often horizontally oriented ulcer on the nasal
philtrum. Most often seen in St Bernards (Figure 6.113).
Mucocutaneous pyoderma: focal areas of depigmentation and crusting. Usually asym-
metrical (differentiation from DLE). Often on alar folds (Figure 6.114).
Nasal pyoderma: primarily haired portions – bridge of the nose yet inflammation
rarely extends onto the nasal planum.
Vitiligo: depigmentation without inflammation or erosion/ulceration (Figure 6.115).
Nasal hypopigmentation: light brown or tan color, may be seasonal, breed fault.
Adverse drug reaction: topical sensitivity (neomycin) or systemic reaction.
Epitheliotropic lymphoma: depigmentation and induration (see Figure 6.93).
Histiocytosis: infiltrates often affect the nares and nasal turbinates; Bernese mountain
dog predisposed (Figure 6.116).
Idiopathic nasodigital hyperkeratosis: often older dogs; nasal planum and marginal
footpads.
Hereditary nasal parakeratosis: labradors, young dogs (see Figure 6.56)
Allergy: mosquito bite hypersensitivity in cats (see Figure 6.79).
Viral: herpes, calici (Figure 6.117).
NODULES AND DRAINING SINUS ETIOLOGY
Bacterial:
Furunculosis secondary toStaphylococcalspp. most common
Actinomyces/nocardia
Mycobacteria