CONDITION
Pemphigus
Pemphigus encompasses a group of autoimmune skin diseases where the immune system attacks the connections between skin cells, causing blistering, crusting, and erosions, with pemphigus foliaceus being the most common form in dogs and cats.
Why this matters now
Pemphigus can develop at any age, though middle-aged animals are most commonly affected. Certain breeds including Akitas, Chow Chows, and Newfoundlands show increased susceptibility. The condition may arise spontaneously or occasionally follow drug administration or other triggers.
The disease typically begins with localised skin changes that progressively spread. Initial lesions may appear minor—small blisters or pustules—but the fragile nature of these lesions means they quickly rupture to form crusts and erosions. Without treatment, the condition tends to spread to involve larger areas of the body, with the face, ears, and footpads commonly affected.
Signals & patterns
Early signals
Pustules on the skin
Small, fluid-filled bumps that may initially be mistaken for infection, often appearing on the face or ears.
Crusting on the nose or ear tips
Yellowish or brown crusts forming on the nose, ear margins, or around the eyes.
Footpad changes
Thickening, cracking, or crusting of the paw pads, sometimes with pain when walking.
Hair loss in affected areas
Patchy areas where fur has fallen out, often with underlying crusting or erosion.
Later signals
Widespread crusting
Extensive crusty lesions spreading across the face, ears, body, and limbs.
Skin erosions and ulcers
Raw, weeping areas where the surface layer of skin has been lost.
Secondary infection
Bacterial colonisation of damaged skin causing additional discharge and odour.
Systemic illness
Lethargy, reduced appetite, and fever may accompany severe or widespread disease.
Click to read about the biological mechanisms
How this is usually investigated
Diagnosis requires demonstrating the characteristic changes within the skin, as the clinical appearance alone can mimic other conditions. Biopsy and microscopic examination are typically necessary.
Clinical examination
Skin cytology
Skin biopsy
Histopathology
Immunofluorescence or immunohistochemistry
Blood tests
Options & trade-offs
Management requires suppressing the autoimmune attack on the skin, typically through immunosuppressive medications, often requiring long-term or lifelong therapy.
Glucocorticoids
Corticosteroids such as prednisolone to suppress the immune response
Trade-offs: Often effective at inducing remission; significant side effects with long-term use; dose adjustments needed; most common first-line treatment.
Steroid-sparing immunosuppressants
Drugs like azathioprine, mycophenolate, or ciclosporin to reduce steroid requirements
Trade-offs: Allow lower steroid doses; take weeks to reach full effect; each has specific monitoring requirements; cost considerations.
Combination therapy
Using multiple immunosuppressive agents together for synergistic effect
Trade-offs: May achieve better control than single agents; increased monitoring needed; requires careful dose adjustment.
Topical therapy
Creams or ointments containing immunosuppressants for localised lesions
Trade-offs: Can help localised disease; reduces systemic medication needs; requires cooperation for application; limited penetration.
Trigger avoidance
Identifying and removing potential triggers such as medications or UV exposure
Trade-offs: Important when triggers identified; may allow dose reduction; not always possible to identify causative factors.
Secondary infection treatment
Antibiotics when bacterial colonisation complicates the condition
Trade-offs: Addresses infection component; culture and sensitivity guide selection; essential for infected lesions.
Common misconceptions
"Pemphigus is a type of allergy"
Pemphigus is an autoimmune disease where the body attacks its own tissues, fundamentally different from allergic conditions despite some visual similarities.
"Skin diseases with crusting are usually infectious and need antibiotics alone"
While secondary infection can occur, pemphigus requires immunosuppressive therapy to address the underlying autoimmune process.
"Animals with pemphigus cannot have good quality of life"
With appropriate treatment, many animals achieve good disease control and maintain comfortable, active lives, though ongoing medication is typically required.
Related conditions
Atopic Dermatitis in Dogs
Atopic dermatitis and pemphigus can both cause chronic skin inflammation and discomfort, though they arise from different immune mechanisms—atopic dermatitis reflects hypersensitivity to environmental allergens, while pemphigus involves autoantibodies attacking skin cell connections. The two conditions may occasionally be considered alongside one another when investigating recurring skin disease, particularly when crust or secondary infection complicates the clinical picture.
Otitis Externa in Dogs
Otitis externa often develops secondary to underlying skin disease, and dogs with pemphigus may experience ear canal involvement as part of the broader pattern of crusting and inflammation. In some cases, persistent or unusual ear disease may prompt investigation for systemic skin conditions including autoimmune processes.
Lymphoma in Dogs
Lymphoma and pemphigus both involve dysregulation of the immune system, and in rare instances immune-mediated skin disease can occur alongside or in response to lymphoid malignancy. The distinction matters because skin lesions in a dog with lymphoma may reflect the cancer itself, a paraneoplastic phenomenon, or a separate autoimmune process.
Hypothyroidism in Dogs
Hypothyroidism has been investigated as a potential contributor to immune dysregulation in dogs, and some older literature suggested an association with autoimmune skin disease, though the evidence for a direct link to pemphigus remains uncertain. Thyroid function may be assessed during the work-up of chronic skin conditions, particularly when multiple body systems appear affected.
Cushings Disease in Dogs
Cushing's disease involves chronic elevation of cortisol, which can alter immune function and skin integrity, and some dogs with pemphigus may develop secondary bacterial or yeast infections that resemble the skin changes seen in hypercortisolism. Distinguishing between primary autoimmune disease and secondary infection in the context of metabolic hormone imbalance can be a relevant diagnostic consideration.
Owners noticing persistent crusty skin lesions, particularly on the face, ears, or paw pads, may recognise these as potentially significant skin changes warranting investigation. Understanding that some skin conditions reflect internal immune dysfunction rather than infection helps frame expectations about diagnosis and management.
Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS