NEW YORK—Rituximab may be an effective treatment for recalcitrant dermatitis herpetiformis (DH), according to a recent case study.
“DH is an autoimmune blistering disease which is commonly associated with celiac disease and can present with debilitating pruritic blisters on extensor surfaces,” explained Dr. Ron Feldman of Emory University School of Medicine.
“The most common treatments are a gluten-free diet along with the addition of dapsone,” he told Reuters Health. “For patients who do not typically respond to these therapies, other immune-suppressing medications have been utilized with mixed results.”
“This is the first successful case of rituximab therapy used for a recalcitrant case of DH,” he said by email. “The patient had resolution of both his pruritus and skin rash. In addition, the levels of both anti-tissue and anti-epidermal transglutaminase antibodies normalized.”
Writing in JAMA Dermatology, online December 28, Dr. Feldman and colleagues describe a man in his 80s with a five-year history of worsening DH. He was put on a gluten-free diet along with dapsone 50 mg daily, but his pruritic rash persisted.
Dapsone was discontinued because of worsening anemia. He began treatment with 3 g sulfasalazine daily, but this was discontinued due to gastrointestinal symptoms.
His disease worsened and became debilitating after stopping sulfasalazine, and he was unable to follow the gluten-free diet that was again recommended. He was put on a tapering course of prednisone from 40 mg to 10 mg daily along with azathioprine titrated up to 2.5 mg/kg daily, but his disease continued to worsen over subsequent months.
He was then treated with rituximab according to the protocol used to treat lymphoma: four weekly infusions of 375 mg/m2.
Thirteen months after treatment, the patient experienced complete resolution of pruritus and other manifestations of DH, as well as normalization of antibodies against both epidermal and tissue transglutaminases.
He went into remission and has remained symptom-free for up to a year and a half thus far.
Dr. Feldman said, “We are excited about this case since rituximab is well tolerated and can potentially provide long lasting remission with removal of pathogenic autoimmune B cells. Although our patient did not have significant gastrointestinal symptoms, we are hopeful that rituximab may provide similar benefits for patients with celiac disease, in which anti-tissue transglutaminase antibodies play a role, although further research will need to be done to confirm this.”
“As we only present a single case, our results of course need to be replicated with a larger group of patients with DH,” concluded Dr. Feldman. “Rituximab has already shown efficacy in the treatment of other autoimmune blistering diseases such as pemphigus and pemphigoid and may have relevance with other B cell mediated diseases in dermatology.”