Small Animal Dermatology, 3rd edition

CHAPTER 12 AUTOIMMUNE BLISTERING DISEASES 191

Vesicles and bullae may persist longer due to thickness of the overlying

epidermis

Rupture leads to deep crateriform erosions progressing quickly to

ulcerations

More severe than PF and PE; patients often ill

Affects mucous membranes, mucocutaneous junctions, and skin; may become

generalized (Figure 12.13)

Positive Nikolsky sign (new or extended erosive lesion created when lateral pres-

sure is applied to the skin near an existing lesion)

Friction and trauma areas (axillae, inguinum, limb pressure points)

Paw pads and nails may slough

Variable pruritus and pain

Anorexia, depression, and fever

Secondary bacterial infections common.

 PEP/Pveg:
Vesicles and bullae develop in all layers of the epidermis, including follicles
Pustule groups become eruptive papillomatous lesions and vegetative masses

(thick, adherent crusts) that ooze (Figure 12.14)

No oral or mucosal lesions

Systemic illness associated with secondary bacterial infection.

 PP:
Very rare
Blistering disease with flaccid pustules, erosions, ulcerations affecting the

mucosae and mucocutaneous junctions as well as haired skin (Figures 12.15–

12.17)

Seen in conjunction with neoplasia

Systemic signs associated both with neoplasia and cutaneous lesions

Reported neoplasia: thymoma, thymic lymphosarcoma, splenic sarcoma.

Pemphigoid Complex

 Signs similar to PV, although blisters are less fragile.

 Chronic, clinically benign disease most common.

 Macules lead to vesicles and bullae that rupture to reveal ulcerations.

 Common sites: head, ears, axillae, ventral abdomen, inguinum.

 Uncommonly affects footpads and ungual folds (Figure 12.18).

 Scarring is common.

 Variable pruritus and pain.

 Anorexia, depression, and fever.

 Mucous membrane pemphigoid:
May be the more common presentation of BP
Symmetrical lesions
Vesicles rapidly lead to ulcerations of the oral cavity, lip margins, periocular,

nasal and genital mucosae (Figure 12.19)

Over 90% of dogs exhibit erosions in more than one mucosal region.