Dupilumab as a novel steroid-sparing treatment for IgG4-related disease

IgG4-related disease (IgG4-RD) is a rare fibroinflammatory, multisystemic condition with a relapsing-remitting progression.1 The level of serum IgG4 correlates with inflammatory activity and organ involvement.1 Glucocorticoids are first line for IgG4-RD, but there are numerous adverse effects with chronic use.2 Dupilumab is a monoclonal antibody that acts on the interleukin 4 (IL-4) receptor alpha, shared by the IL-4 and IL-13 receptors.1 IL-4 causes isotype switching from IgM to IgG4 and IL-13 is implicated in fibrosis.3 Thus, it was postulated by the authors to investigate dupilumab as a novel steroid-sparing treatment for IgG4-RD. A 67-year-old man with no known allergies and a history of sensory neural hearing loss, recurrent bronchitis, spinal stenosis, moderate positional obstructive sleep apnoea, asthma, atopic dermatitis (which caused swelling around his eyes) and allergic rhinoconjunctivitis underwent extensive investigations over the past 2 years due to suspected IgG4-RD. The patient’s initial complaint was pruritic erythematous lesions on the legs, arms, chest and palms. …