Recognizing the Clinical and Pathophysiologic Overlap Between Allergy and Lupus

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease characterized by diverse and evolving clinical manifestations, often resulting in delayed diagnosis and increased morbidity. Although traditionally viewed as distinct, allergic and autoimmune diseases share overlapping immunologic pathways and clinical features. Symptoms commonly encountered in allergy practice, including urticaria, angioedema, and pruritus, may represent early or coexisting manifestations of underlying lupus rather than primary allergic disease. This narrative review examines the clinical and pathophysiologic overlap between allergy and lupus, with a focus on presentations that may bring patients with undiagnosed SLE to the allergy setting. Shared mechanisms, including complement dysregulation, autoreactive IgE, and mast cell activation, are discussed as contributors to overlapping symptomatology. Key clinical features that distinguish lupus-associated presentations from primary allergic conditions are outlined, along with associated systemic findings that should prompt further evaluation. A practical approach to assessment is emphasized, including targeted history, judicious use of serologic testing, and indications for dermatologic and rheumatologic referral. Improved recognition of these patterns in allergy practice may facilitate earlier diagnosis, reduce unnecessary testing, and improve patient outcomes.