INITIAL TREATMENT CONSIDERATIONS
Pemphigus foliaceus is often a chronic skin condition with a waxing and waning course. Clients should be aware of the possibility
of disease recurrence after remission. Because of the potential side effects of medications, doses should be tapered in response
to clinical signs.
It is important to educate clients about medication side effects so that they understand why medication doses need to be tapered.
Remind clients that pemphigus foliaceus flares may occur after decreasing the medication dose. Without client education, it
is easy for owners to become frustrated and perceive that the medications are not helping. The long-term costs of recheck
examinations and tests to monitor pemphigus foliaceus patients receiving therapy can also be high. A client handout can help
educate owners about pemphigus foliaceus (to download a handout, go to
http://www.dvm360.com/pemphigus).
Once clients have been fully informed of the prognosis and medication side effects of treatment, initiate pemphigus foliaceus
treatment. No set protocol exists for treating canine and feline pemphigus foliaceus. Instead, medications and their doses
need to be selected for each individual patient based on the severity of clinical signs and the medications' efficacy and
side effects.
Canine cases of pemphigus foliaceus with localized skin lesions may be managed with topical glucocorticoids. In mild cases,
topical glucocorticoids can be used alone. In more severe cases, topical glucocorticoids can be used to minimize the dose
of systemic immunosuppressive therapy. Topical glucocorticoids are less commonly used in cats because it can be more difficult
to apply topical medications to cats. In most dogs and cats, systemic immunosuppression remains the initial treatment of choice
for pemphigus foliaceus. Concurrent systemic antibiotic therapy should be considered if there is a bacterial skin infection.
MEDICATIONS USED FOR PEMPHIGUS FOLIACEUS
Glucocorticoids
Topical glucocorticoids can be used as monotherapy for mild cases of pemphigus foliaceus, especially in dogs with localized
facial lesions. They can also be used in combination with other systemic medications in more refractory cases. A variety of
glucocorticoids more potent than hydrocortisone have been used topically for pemphigus foliaceus such as betamethasone or
triamcinolone, both of which are available in a variety of concentrations. Since glucocorticoids can cause skin atrophy, protect
the area of glucocorticoid application from trauma. Mild skin atrophy can be managed by switching to a lower-potency topical
glucocorticoid. More severe skin atrophy should be managed by stopping all topical glucocorticoids.
Systemic immunosuppression with glucocorticoids provides the most rapid clinical response in dogs and cats with pemphigus
foliaceus. Prednisone is initially started at 2 mg/kg/day orally in dogs, and prednisolone is initially started at 2 to 4
mg/kg/day orally in cats. The dose of prednisone or prednisolone may then be increased if no improvement in clinical signs
is evident within one or two weeks. Cats may respond better to glucocorticoids other than prednisone because of the lower
bioavailability of prednisone compared with other glucocorticoids in cats.48 If glucocorticoids of different potencies are used, equivalent doses should be calculated. In cats, triamcinolone can be
initially dosed at 2 to 4 mg/kg/day orally, and dexamethasone can be initially dosed at 0.3 to 0.6 mg/kg/day orally. The glucocorticoid
dose should be selected based on the clinical signs. Dogs and cats with mild pemphigus foliaceus lesions may respond to lower
doses of glucocorticoids.
Long-acting injectable glucocorticoids such as methylprednisolone acetate (Depo Medrol—Pfizer Animal Health) are not recommended
for treating pemphigus foliaceus; the dose of any immunosuppressive medication should ideally be adjusted in response to the
patient's clinical signs.
Dermatologists occasionally use high-dose pulse oral and intravenous glucocorticoid administration to treat pemphigus foliaceus
in dogs. These high dosages (oral prednisone at 10 mg/kg/day49 or intravenous methylprednisolone succinate at 11 mg/kg/day50 ) are typically given for three days followed by a much lower dose of oral prednisone (0.5 to 2 mg/kg/day). High-dose glucocorticoid
administration is used primarily in severe pemphigus foliaceus cases in which quick remission of signs is required. Relapse
is still possible once the glucocorticoid dose is decreased. At this time, high-dose pulse glucocorticoid therapy should be
considered experimental; further studies are needed to demonstrate its benefit.
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