Bullous Pemphigoid

Introduction

Bullous Pemphigoid is an autoimmune disease, affecting dogs, cats, horses and pigs. It is very rare. The disease causes subepidermal vesicular dermatitis. The target autoantigen is a protein located in the basement membrane, hence immune attack leads to seperation of the epidermis and dermis.
Vesicles and bullae appear on the skin but these quickly rupture to leave large erosions on the skin surface. Typical areas lesions are seen are around mucocutaneous junctions especially in the axillae and groin, but may also affect solely the mucous membrane in certain areas such as the oral cavity.

Signalment

Dogs, cats, horses and pigs can be affected by this disease, but it s rare in all these species. There are no breed predilections. Females are thought to be more likely to have autoimmune disease than males. Autoimmune disease usually arises at around 1- 3 years of age.

Clinical Signs

Vesicles and bullae on the areas mentioned above are indicative of a subepidermal vesicular dermatitis. In severe cases the animal may be depressed, lethargic and pyrexic.

Diagnosis

History and clinical signs may place this disease on the differential list. Other differentials include other ulcerative autoimmune diseases such as Pemphigus vulgaris and systemic lupus erythrematosus.
A biopsy of the lesion would demonstrate the presence of the disease. Immunopathology would reveal linear Ig deposition at the basement membrane.

Treatment

High dose of systemic glucocorticoids is required for treatment of this disease.

Prognosis

Guarded.

References

Blood, D.C. and Studdert, V. P. (1999) Saunders Comprehensive Veterinary Dictionary (2nd Edition), Elsevier Science
Bond, R. (2008) Veterinary Dermatology Study Guide, Royal Veterinary College
Foster, A, and Foll, C. (2003) BSAVA small animal dermatology (second edition), British Small Animal Veterinary Association
Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition), Merial