Should we follow the penicillin allergy label trail in approaching patients with a sulfonamide allergy label?

Background: A penicillin allergy label increases the risk of hospitalization, length of hospital stays, and even mortality rate. This recognition has led to recommendations for proactive evaluation of penicillin allergy and de-labeling efforts. Less is known about the impact of the sulfonamide allergy label (SAL), the second-most-common antibiotic allergy label, on morbidity and mortality of patients and the impact on the health-care system. Further, the approach to patients with an SAL is not well characterized. Objective: We aimed to review recent evidence that examined the association between an SAL and clinical outcomes, including health-care utilization. We also aimed to review the evolving approach to an SAL, including the incorporation of decision tools and identifying patient populations that may benefit from proactive evaluation. Methods: We performed a narrative review of the literature. Results: There is increasing evidence that supports a negative impact for having an SAL on clinical outcomes. An SAL influences antibiotic prescription practices and is associated with an increased risk of opportunistic infections and urinary tract infections among recipients of solid organ transplantation and a small increase in the risk of complications from cystitis. The recent development and validation of the clinical decision tool, trimethoprim-sulfamethoxazole allergy clinical decision rule (SULF-FAST), and the proven feasibility and safety for direct oral challenge present an opportunity to offer proactive evaluation of individuals who might benefit from sulfonamide antibiotics such as individuals who are immunosuppressed, patients with recurrent urinary tract infections, or those with multiple antibiotic allergies. Conclusion: Proactive evaluation and de-labeling of sulfonamide allergy through direct oral challenge with trimethoprim-sulfamethoxazole could be considered in patients who are immunocompromised, patients with recurrent acute cystitis, and those with multiantibiotic allergy. Further research is needed to identify systematic hospital-wide interventions and to elucidate the benefit of such de-labeling on clinical outcomes.