Changes

==Introduction==

==Introduction==

Pemphigus foliaceus is an '''autoimmune disease''' in which '''autoantibodies''' are directed against components of the epidermis resulting in separation of the epidermal cells (acantholysis) and subcorneal vesicle formation.

Pemphigus foliaceus is an [[:Category:Autoimmune Diseases|'''autoimmune disease''']] in which '''autoantibodies''' are directed against components of the epidermis resulting in separation of the epidermal cells (acantholysis) and subcorneal vesicle formation. It is one of the [[Pemphigus]] complex of diseases.  

It is a '''pustular skin disease''' and should be considered in cases which are non-responsive to antibiotics and where pustules are found in areas where staphylococcal pustules are rarely seen (eg the pinnae).

It is a '''pustular skin disease''' and should be considered in cases which are non-responsive to antibiotics and where pustules are found in areas where staphylococcal pustules are rarely seen (eg the pinnae).

==Pathogenesis==

==Pathogenesis==

Autoantibodies are directed against a component of '''desmosomes''', which are the main intracellular bridges between the keratinocytes and are responsible for cell-to-cell cohesion. There is '''loss of cohesion between keratinocytes''' and there is acantholysis and pustule formation.  

Autoantibodies are directed against a component of '''desmosomes''', which are the main intracellular bridges between the keratinocytes and are responsible for cell-to-cell cohesion. There is '''loss of cohesion between keratinocytes''', acantholysis and pustule formation.  

A pemphigus foliaceus-like disease can be '''initiated by drug therapy'''. If the disease resolves when the drug is stopped it is called 'pemphigus foliaceus-like drug reaction' and if the disease persists after the drug is stopped it is called 'drug-induced pemphigus foliaceus'.

A pemphigus foliaceus-like disease can be '''initiated by drug therapy'''. If the disease resolves when the drug is stopped it is called 'pemphigus foliaceus-like drug reaction' and if the disease persists after the drug is stopped it is called 'drug-induced pemphigus foliaceus'.

'''Trimethoprim-sulpha''' is responsible in dogs, and in cats, doxycycline, ampicillin, cimetidine and methimazole have been implicated.

'''Trimethoprim-sulpha''' is responsible in dogs, and in cats, doxycycline, ampicillin, cimetidine and methimazole have been implicated.

==Clinical signs==

==Clinical Signs==

The disease is usually of '''gradual onset''' and presents as a '''vesicobullous or pustular dermatitis''' with secondary erythema, scale, alopecia, erosion and crust formation. Epidermal collarettes are common.

The disease is usually of '''gradual onset''' and presents as a '''vesicobullous or pustular dermatitis''' with secondary erythema, scale, [[alopecia]], erosion and crust formation. Epidermal collarettes are common.

The lesions may be distributed evenly over the body, usually in a symmetrical way, including the '''pinnae and the bridge of the nose'''.

The lesions may be distributed evenly over the body, usually in a symmetrical way, including the '''pinnae and the bridge of the nose'''.

==Differential Diagnoses==

==Differential Diagnoses==

Demodicosis

:[[Demodicosis]]

 

:[[Superficial Pyoderma|Superficial pyoderma]]

Superficial pyoderma

:[[Zinc Deficiency|Zinc responsive dermatitis]]

 

:[[Dermatophytosis]]

Zinc responsive dermatitis

:Epitheliotropic [[lymphoma]]

 

:Drug eruption

Dermatophytosis

:[[Systemic Lupus Erythematosus|Systemic lupus erythematosus]]

 

Epitheliotropic lymphoma

 

Drug eruption

 

Systemic lupus erythematosus

==Diagnosis==

==Diagnosis==

Demodicosis and dermatophytosis can be ruled out with '''skin scrapes'''.

Demodicosis and dermatophytosis can be ruled out with '''skin scrapes'''.

'''Immunofluorescence''' can be used in cases where histopathology is not diagnostic.

'''[[Immunofluorescence]]''' can be used in cases where histopathology is not diagnostic.

==Treatment==

==Treatment==

'''Baseline haematology and biochemistry''' should be obtained prior to starting any therapy.

'''Baseline haematology and biochemistry''' should be obtained prior to starting any therapy.

Suppression of clinical signs can usually be achieved with '''immunosuppressive doses of prednisolone'''. Doses can be increased if there is no response.

Suppression of clinical signs can usually be achieved with '''immunosuppressive doses of prednisolone'''. Doses can be increased if there is no response. Once remission is achieved, the dose can be slowly tapered and nearly half the cases can usually be maintained on alternate-day therapy. The majority of feline cases response well to prednisolone therapy and can be maintained in clinical remission.  

A significant proportion of dogs may fail to respond to glucocorticoid therapy and may require additional drugs. '''Azathioprine''' is a useful steroid-sparing drug in dogs. The beneficial effects may not be apparent for 3-5 weeks. Azathioprine is contraindicated in cats. In dogs, side effects include: bone marrow suppression, gastrointestinal effects.

 

 

A significant proportion of dogs may fail to respond to glucocorticoid therapy and may require additional drugs.  

 

'''Azathioprine''' is a useful steroid-sparing drug in dogs. The beneficial effects may not be apparent for 3-5 weeks.  

 

Azathioprine is contraindicated in cats.  

 

In dogs, side effects include: bone marrow suppression, gastrointestinal effects.

'''Chlorambucil''' can be used as a steroid-sparing drug in both dogs and cats. It is sometimes used as a sole agent in cats.

'''Chlorambucil''' can be used as a steroid-sparing drug in both dogs and cats. It is sometimes used as a sole agent in cats.

Hedlund, C. (2002) '''Clinical atlas of ear, nose and throat diseases in small animals''' ''Schlütersche''

Hedlund, C. (2002) '''Clinical atlas of ear, nose and throat diseases in small animals''' ''Schlütersche''

 

[[Category:To Do - Review]]

[[Category:Expert Review - Small Animal]]

[[Category:Antibody Mediated Autoimmune Diseases]]

[[Category:Antibody Mediated Autoimmune Diseases]]