Treatment-resistant cough: a rare manifestation of IgG4-related disease involving the larynx.

IgG4-related autoimmune diseases (IgG4 RD) are a relatively recently recognised group of disease processes that can affect multiple organ systems and result in protean symptoms. Here, we present a rare case of a 69-year-old man with a history of IgG4 RD affecting his lacrimal gland and pancreas who developed symptoms of severe laryngitis not responsive to usual therapy. He presented with non-productive cough, hoarseness and dyspnoea. Imaging findings suggestive of aortitis and laryngeal inflammation in the setting of his IgG4 RD history prompted treatment with rituximab, which resulted in resolution of his laryngeal symptoms. Subsequently, his cough returned and he required periodic rituximab infusions to stay symptom-free. IgG4 RD of the larynx is an uncommonly reported manifestation in literature. This disease is very responsive to anti-CD20 monoclonal antibody treatment. IgG4 RD should be considered in patients with airway symptoms that are especially refractory to usual therapy.