INTRODUCTION
By 1970, systemic corticosteroids, the mainstay therapy of patients with pemphigus vulgaris, had reduced the disease's
mortality rate from nearly 100% to approximately 24%.1 The addition of “adjuvant,” corticosteroid-sparing immunosuppressant
agents (ISA), coupled with advances in the management
of complications, further reduced mortality below 10%.2 However, even with co-administration of immunosuppressive adjuvants, prolonged high doses of systemic corticosteroids are often required. Complications of conventional therapy have become
the main causes of death in pemphigus.1-3 Although the evidence
for biologic agents in the treatment of this disease is limited to case reports, case series and open-label trials, there is enough efficacy and safety profile data on these agents to consider reappraisal
of the conventional treatment of pemphigus vulgaris.
Conventional Therapy
The treatment for pemphigus is largely empirical with no universal
consensus on corticosteroid dosing. The British Association of Dermatologists recommends treatment with prednisone doses of 40 mg to 60 mg daily, and higher doses (60 mg to 100 mg daily) for undefined “more severe cases.” 4 If an adequate therapeutic response
has not been achieved within 5 to 7 days after initiation of corticosteroid treatment, the dose is then increased in 50% to 100% increments until the disease is controlled, as manifested by healing of erosions and suppressed formation of vesicles or bullae.2,4 Once disease remission is induced and maintained, the corticosteroid dose is reduced by 50% every two weeks.2 It is interesting that, despite limitations in size and study design, a randomized-
controlled trial that compared doses of 1 mg per kg (120 mg to 180 mg per day) and 0.5 mg per kg (45 mg to 60 mg per day) of oral prednisone in 22 cases of severe pemphigus demonstrated no significant difference either in the treatment duration needed to attain disease remission or the 5-year relapse rate.5
Pemphigus patients develop numerous complications directly related to systemic corticosteroids. A 20-year review of over 100 patients with pemphigus reported increased rates of infections, thromboembolic events and psychosis associated with doses of prednisone higher than 120 mg per day.1 Chronic corticosteroid administration was associated with long-term morbidity that included
radiographically diagnosed osteoporosis in 29% of cases, gastrointestinal adverse events in 11%, psychiatric events in 33%, and diabetes in 41%.1 Pemphigus cases invariably require high doses, which cause adverse effects that not only produce symptoms,
but can reduce life span. Between 10% and 40% of persons on high-dose corticosteroid therapy develop overt diabetes mellitus,
which may appear in the first six weeks of therapy,6 and approximately 20% of cases become newly hypertensive. While the risk of corticosteroid-related complications is lower at doses equivalent to 10 mg of prednisone daily, due to variability in the response of individuals to corticosteroids, complications can develop
at relatively low doses. Between 30% and 50% of patients treated with long-term therapy without prophylaxis develop osteoporosis. In women, bone density in the lumbar spine is reduced
between 20% to 50% with prolonged daily corticosteroid doses equivalent to 30 mg of prednisone and 10% to 20% with daily doses of 10 mg or less. Observational studies suggest that up to half of patients treated with chronic corticosteroids develop fractures, which are often asymptomatic.7 Even after only one year of treatment, the incidence of new fractures can be as high as 17%.8 In a retrospective cohort study comparing patients on long-term corticosteroids to healthy persons, the risk of fractures was found to be increased by 1.55-fold for daily prednisone doses lower than 2.5 mg and 2.59-fold for doses between 2.5 mg to 7.5 mg.9 Because bone density is most significantly decreased within the first 6 to 12 months of therapy, the duration of corticosteroid treatment should be limited to less than a year7 and preventive
