Antibiotic allergy labels in immunocompromised populations.

Antibiotic allergy labels (AALs) are commonly reported, with well-defined prevalence in the general population; several studies have now focused efforts on immunocompromised hosts. Understanding the prevalence of reported allergy labels and methods of antibiotic allergy evaluation and delabeling strategies has the potential to improve prescribing practices and clinical outcomes in this high-antibiotic use group. In this review, we will discuss the current literature on the prevalence, impact, and evaluations of AALs in immunocompromised hosts with a focus on beta-lactam (penicillin) allergy and sulfa-antibiotic (antimicrobial sulfurs) allergy labels.

Drug Allergy Mimics.

When approaching a case of apparent drug allergy, the consulting clinician should consider a broad differential diagnosis. This article presents a series of cases that could be commonly referred to an allergist for assessment as "drug allergy," however, a real diagnosis exists that mandates a different diagnostic and treatment strategy, including a case of inducible laryngeal obstruction, multiple drug intolerance syndrome, viral rash, seizure due to metastatic malignancy, and hemophagocytic lymphohistiocytosis initially diagnosed as drug reaction and eosinophilia with systemic symptoms. The initial misdiagnoses of these patients delayed or interfered with their medical care, emphasizing the importance of accurate diagnoses for the benefit of our patients.

Hypersensitivity and Immune-related Adverse Events in Biologic Therapy.

Biologic medications are an expanding field of therapeutics for various medical conditions including cancer and inflammatory diseases. Due to their targeted approach to therapy, biologics can be less toxic than traditional systemic medications. However, as use becomes more widespread, adverse effects from biologic administration have also become apparent. Immune-related adverse events are a common mechanism by which biologics can cause on-target immune-related toxicities and both immediate and delayed-type hypersensitivity reactions. Immediate hypersensitivity reactions can be mediated by cytokine release or antibody mediated reactions, while delayed-type hypersensitivity is most often caused by serum sickness-like reactions. Additionally, biologics used for treatment of cancer using checkpoint blockade and rheumatologic disease using cytokine blockade can result in autoimmunity. Finally, when inflammatory cytokines are targeted for treatment of autoimmune or autoinflammatory disease, the host immune defense can be compromised predisposing to secondary immunodeficiency. This review will discuss the mechanisms of these reactions and discuss examples of biologics implicated in each of these adverse events.

Development and Validation of a Sulfa Antibiotic Allergy Clinical Decision Rule.

This cohort study describes the adaptation of a widely used penicillin allergy clinical decision tool for evaluation of trimethoprim-sulfamethoxazole allergy.