Small Animal Dermatology, 3rd edition

CHAPTER 12 AUTOIMMUNE BLISTERING DISEASES 195

 Immunopathology of biopsied skin via immunofluorescent antibody assays or

immunohistochemical testing.

Results can be affected by concurrent or previous corticosteroid (or other

immunosuppressive drug) administration.

Indirect immunofluorescence usually negative.

PF: positive staining for Dsg1 in the superficial epithelia in 50–90% of cases.

PE may demonstrate staining of basement membranes and intercellular spaces.

PV: positive staining for Dsg3 in the deep epithelia.

PP: positive staining for one or both Dsg1 and Dsg3 with desmoplakin.

Pathologic Findings – Pemphigoid Complex

 Subepidermal vesicle.

 Predominantly eosinophilic inflammatory infiltrate; numbers significantly lower with

MP.

 No acantholytic keratinocytes: defect is subepidermal.

 Dermal and submucosal inflammation due to secondary infection or insult.

 Direct immunofluorescence positive at the BMZ.

Pathologic Findings – Epidermolysis Bullosa Acquisita

 Subepidermal vesicle.

 Predominantly acellular.

 No acantholytic keratinocytes: defect is subepidermal.

 Neutrophilic dermal infiltrate.

 Direct immunofluorescence positive at the BMZ.

THERAPEUTICS

General Considerations

 Initial inpatient supportive therapy for severely affected patients.

 Outpatient treatment with initial frequent hospital visits (every 1–3 weeks); taper to

every 1–3 months when remission is achieved and the patient is on a maintenance

medical regimen.

 Severely affected patients may require antibiotics based on culture and sensitivity

testing.

 Hydrotherapy and soaks very helpful and soothing.

 Avoid ultraviolet light – may exacerbate lesions (especially PE).

Drugs of Choice – Pemphigus Complex

 PF and PV:
Corticosteroids:
Prednisolone: 2.2–6.6 mg/kg/day PO divided BID to achieve clinical remis-
sion; alternative pulse dose therapy: 10 mg/kg q24h for 3 days followed by
standard dosing at 2.2 mg/kg/day