Non-ß-Lactam Antibiotic Hypersensitivity Reactions.

OBJECTIVES: Antibiotics are among the most common prescriptions in children, and non-ß-lactam antibiotics (NBLAs) account for almost half of those prescribed in Australian pediatric hospitals. Despite this, data on NBLA hypersensitivity in children are limited. This study describes reported hypersensitivity reactions to NBLAs in children and the results of allergy evaluation. METHODS: Children with a suspected NBLA allergy who had skin testing and/or an intravenous or oral challenge test (OCT) between May 2011 and June 2018 were included. Patients were excluded if they were >18 years old or did not complete the allergy evaluation for any reason other than allergic reaction. RESULTS: Over the 7-year study period, 141 children had 150 allergy evaluations of 15 different NBLAs. The median time from the initial reported reaction to allergy evaluation was 1.9 (range 0.1-14.9) years. Overall, 27 of the 150 (18.0%) challenge tests to NBLAs had positive results, with the rate of positive OCT results being highest for trimethoprim-sulfamethoxazole (15 of 46; 32.6%) and macrolides (8 of 77; 10.4%). Although 4 children reported initial anaphylactic reactions, no patients had severe symptoms on rechallenge or required adrenaline. Of the challenges that had positive results, the majority of children (23 of 27; 85.2%) had symptoms on repeat challenge similar to those that were initially reported. CONCLUSIONS: Overall, 8 of 10 children with NBLA allergy could be delabeled. On average, patients waited 1.9 years to be rechallenged. Timely access to allergy evaluation to delabel these patients is needed to preserve first-line antibiotics.

Nonvisualized sentinel lymph nodes on lymphoscintigraphy in melanoma: predictive factors and surgical outcomes.

PURPOSE: Preoperative lymphoscintigraphy is the standard for the identification of sentinel lymph nodes (SLNs) in melanoma. The impact of negative scintigraphy [nonvisualization (NV) of the SLN] on surgical outcomes is inadequately reported in the literature. The objectives of this study were to determine the incidence, predictive factors, and surgical outcomes of NV in clinically node-negative melanoma patients. PATIENTS AND METHODS: A retrospective review of a prospective, Institutional Review Board approved, melanoma sentinel node database from January 2005 to August 2015 was performed. RESULTS: Twenty-seven of the 897 (3%) patients had negative scintigraphy. Single-photon emission computed tomography/computed tomography was performed in addition to planar imaging in four patients and failed to locate the SLN in all cases. NV was associated with older age (71 vs. 59 years, P<0.001), head and neck primaries (41%), and previous operations adjacent to the primary tumor or nodal beds (37%). NV was not associated with sex, BMI, or T stage. Despite a negative scintigram, the SLN was still found at operation in 10 of the 27 (37%) patients using the hand-held gamma probe, with one (10%) patient having nodal metastasis. Two patients with NV had nodal recurrence, with a mean follow-up of 3 years. DISCUSSION: Preoperative lymphoscintigraphy in clinically node-negative melanoma patients is associated with a low NV rate. Predictors for NV include age, head and neck location, and previous operations at adjacent sites. NV should not preclude surgical exploration as the SLN can still be found at operation in over one-third of patients.