Personalized Management of Chronic Rhinosinusitis in the Context of Immune Deficiency.

Primary and secondary immunodeficiency as a cause of recalcitrant or difficult to treat chronic rhinosinusitis (CRS) and recurrent acute rhinosinusitis (RARS) are under-appreciated etiologies. Patients with persistent symptoms, frequent exacerbations despite appropriate medical therapy, or other sinopulmonary conditions known to be related to an immunodeficient state warrant further testing for immunodeficiency, as up to 20% of this cohort of patients may have underlying immunodeficiency. Testing for immunodeficiency includes CBC with differential, immunoglobulin levels, and pneumococcal vaccine titres before and after administration. Regarding secondary immunodeficiency, these patients may present with atypical symptoms, harbor atypical bacteria, or even present with severe complications with orbital or intracranial spread of disease, particularly in the context of acute bacterial rhinosinusitis. While reversal of the underlying cause of immunodeficiency is optimal, in this group of patients, it may not be practical or possible. Thus, familiarity with treatment options for these patients is paramount to personalized care. Patients with CRS who also have an underlying immunodeficiency require additional and specialized care compared to their immunocompetent counterparts. This includes pneumococcal vaccination against common encapsulated pathogens, judicious and timely use of antibiotics during complications and prophylactically, immunoglobulin replacement therapy, and consideration of endoscopic sinus surgery. Ultimately, clinicians must appropriately identify immunodeficiency disorders, thus allowing for a precise and personalized approach depending on the underlying pathophysiology and reasons for recalcitrant disease.