Pemphigus In Dogs – Symptoms, Treatment And Affected Breeds

Pemphigus foliaceus is a potentially life-threatening, autoimmune, blistering, pustular, or vesiculobullous skin disease characterized by the presence of circulating autoantibodies against epidermal intercellular adhesion of the keratinocytes.

Pemphigus is coined from the Greek ‘pemphix’, which means bubble or blister. The three major forms are pemphigus Vulgaris, pemphigus foliaceous, and paraneoplastic pemphigus. Pemphigus foliaceus is the most common variant of pemphigus diseases, which are groups of IgG-mediated autoimmune diseases of stratified squamous epithelia, characterized by autoantibodies that are directed against keratinocyte desmosomal proteins, leading to acantholysis (the loss of cell adhesion).

Cadherin family of cell-cell adhesion molecules (such as Desmoglein 1 and desmoglein 3) that are found in desmosomes are the structures mainly responsible for maintaining intercellular adhesion.

Acantholysis of these adhesion molecules causes separation and loss of integrity of the epidermal cell layers, resulting in transient blisters and/or pustules that often contain free-floating loose keratinocytes which quickly develop into scales, erosions, crusts, and alopecia on the mucous membranes and/or skin.

Pemphigus foliaceous (PF) blisters occur in the superficial layers of the epidermis called desmoglein-1 (Dsg1) whereas pemphigus Vulgaris (PV) blisters develop deep in the oral epithelium above the basal layer or epidermis and have typically if not only, anti-desmoglein 3 (Dsg 3) autoantibodies. Paraneoplastic pemphigus develops in mucosal and cutaneous layers due to anti-desmoglein 3 and/or anti-desmoglein 1 IgG autoantibodies together with interface dermatitis.

Mucosal lesions are classically present in pemphigus Vulgaris, whereas in pemphigus foliaceus there is only skin involvement without mucosal lesions.

• Superficial, Small, and Transient Pustules.
• Skin Erosions and crusts, sometimes itchy.
• Thick (multilayered), Yellow-brown crust (scabs).
• Alopecia
• Lesions can coalesce or cluster to form different patterns.
• Lethargy
• Pyrexia, Hyporexia or Anorexia
• Weight Loss

Control of the induction (affector) part of the immune response:

This is focused on the suppression of the aberrant responses of the dog's immune system that is liable for the production of antibodies or cytokines directed against normal tissue.

Examples:

• Corticosteroids like oral prednisone or methylprednisolone.
• Alternative steroids for prednisone- and methylprednisolone-refractory cases include dexamethasone and triamcinolone.
• Immunosuppressive drugs, such as cyclosporine, azathioprine, or chlorambucil.
• Nonsteroidal immunosuppressive drugs include tetracycline/niacinamide and gold salts.

Control the inflammation (effector phase) and/or maintenance period:

Once induction is reached, medications are tapered gradually and treatment is more focused on maintenance of equilibrium state and control of inflammation. In many situations, however, autoimmune disease is treated on an outpatient basis.

1. It is best to avoid the allergens altogether. Pollens and dust ( use an air cleaner with a HEPA filter), Molds (place activated charcoal above the exposed dirt in your house plants or use a dehumidifier).
2. Medicated Baths: Medicated baths (weekly or every other week) with medicated shampoos and antimicrobial and antifungal agents relieves injured skin and remove allergens that cause skin allergy flare-ups. Afterward, apply a rinse to prevent drying out of the skin and hair coat.
3. Dogs with skin folds can be cleaned daily with a clean, damp cloth, shampoo, wipes, ointment, lotion, spray, skin cleanser, etc.
4. Regularly brush the dog to reduce shedding. Consistent grooming spreads the skin’s natural protective oils across the surface.

• There is no means of preventing or avoiding PF save genetic counseling.
• Screening of highly affected breeds prior to breeding is strongly recommended.
• Never skip check-ups.
• Feed a home-prepared diet of pasture-fed, organically produced ingredients.
• When your dog has been prescribed a dosage, taper off slowly or else you might experience withdrawal symptoms.

Akita, Chow Chow, Cocker Spaniel, Bearded Collie, English Bulldog,English Springer Spaniel, German Shepherd, Newfoundland, Schipperke, Dachshund, Doberman Pinscher, Newfoundland, Middle Age Dogs

1. Risk Factors:

• Mostly Congenital / Idiopathic.
• Allergic Skin Diseases (e.g., Flea Allergy Dermatitis, Atopic Dermatitis).
• Reported drugs associated with PF include antibiotics (e.g., sulfonamides, penicillins, cephalosporins).
• Topical ectoparasitic preparations containing fipronil, metaflumizone, amitraz, dinotefuran, S methoprene, permethrin, or pyriproxyfen.
• Concurrent systemic disease (e.g., cutaneous polyautoimmunity with simultaneous PF).
• Over Sunlight Exposure.

2. Types:

1. Natural Form Pemphigus Folieaceus:

• Genetic predisposition is noticed in a few breeds.
• Chow chows and Akitas are overrepresented.

2. Drug-Induced Form:

• A drug-induced type often mimics the congenital condition with some variations, such as oral involvement, sudden onset, and early age.
• Drugs commonly implicated are antibiotics.
• Dogs that undergo long-term treatment for chronic skin conditions like allergies also are at risk.
• Doberman Pinscher and Labrador Retriever.

3. Morbidity:

• For most dogs, lesions usually appear first on the face and advance to other body sites such as the feet/footpads and trunk.
• Lesions may also appear commonly in other parts of the body or become generalized.
• Few PF variants are restricted to the face or footpads or to the trunk only. i.e. Lesions are concentrated on only a few localized areas of the body without affecting other regions.
• The course of the disease might be progressive with either slow (within months or years) or a rapid (within days or weeks) onset of clinical signs, or it may fluctuate with waves of pustule formation.
• Classic histopathologic traits of pemphigus foliaceous are superficial epidermal and intrafollicular (intragranular or subcorneal) pustules with the increased prominence of the granular layer and loss of the stratum corneum.
• In a recent study, histopathologic findings reveal that dogs with systemic signs also have vasculopathy or vasculitis for which clinical remission took longer to achieve.
• Pustules usually have a large number of Neutrophils and mostly they appear intact (non-toxic or non-degenerate).

4. Mortality:

Pemphigus foliaceus is a potentially life-threatening autoimmune disease in dogs with a mortality rate of dogs not documented.

5. Diagnosis:

• Routine Hematology
• Surgical Biopsy
• Histopathological examination of the skin.

6. Differential Diagnosis of Pemphigus Foliaceus:

• Pemphigus Vulgaris
• Acantholytic Actinic Keratosis
• Staphylococcal Scalded Skin Syndrome
• Herpetiform Pemphigus

7. Prognosis:

In many clinical studies, the mean age of onset of PF in dogs is 4 years. If not treated, pemphigus foliaceus is often fatal disease. Most of the dogs present with only scaling, crusted and erythematous plaques (on the head, neck, and trunk) due to the superficial nature of the blisters. The prognosis for PF is distinctly better than for those with PV, while dogs with more severe PF do occasionally die as a result of infections. The prognosis (fair to good) is possibly secondary to the PF blistering process that is more superficial in nature.

Time to visit the vet clinic for an examination, if you notice any of the following:

• Open sores around the head, face, and ears.
• Fluid-filled blisters.
• Itchy Skin erosions and crusts.

• Choose a wholesome food, minimally-processed, that is free of preservatives, chemicals, hormones, and other toxic additives. Keep away from butylated hydroxyanisole (BHA) and ethoxyquin.
• An allergen-free (hypoallergenic) balanced diet (check for thickeners, coatings, flavors).
• Try an elimination diet after food sensitivity testing. Many prescribed medications for an autoimmune disease can cause GI and non-GI woes.
• Consider a diet with all essential nutrients and also provides plenty of antioxidants (combat free radicals).
• Consider a probiotic supplement with added support for the liver.

In general, Over 75% of dogs with PF conditions can be satisfactorily managed. It is usually a lifelong condition requiring continuous management.

After immunosuppressive therapy is tapered and discontinued, some dogs may remain in remission and they require lifelong therapy to maintain remission. Usually, the prognosis for dogs with PF remains good depending on the response to therapy, adverse response to treatment, and co-morbidities.