Case Report: A rare co-occurrence of IgA pemphigus and pyoderma gangrenosum associated with IgA-κ type monoclonal gammopathy of undetermined significance: a 19-year diagnostic and therapeutic journey

We report a complex case of neutrophilic dermatosis (ND) in a 61-year-old woman with a 19-year history of recurrent, pruritic, and painful vesiculopustular eruptions. Her clinical course was marked by evolving diagnoses, from pustular vasculitis to IgA pemphigus and pyoderma gangrenosum (PG). Concurrent investigations revealed an IgA-κ type monoclonal gammopathy of undetermined significance (MGUS). This case highlights the rare association between neutrophilic dermatoses (ND) and haematological disorders, and illustrates the therapeutic challenges posed by comorbidities such as osteoporosis and a history of tuberculosis. Management with dapsone and low-dose corticosteroids led to significant clinical improvement.