D1.33 - Patient-reported outcomes following beta-lactam antibiotic allergy delabeling work-up

Beta-lactam antibiotic allergy is one of the most frequently reported drug allergies, although true hypersensitivity is confirmed in much fewer cases. Inaccurate allergy labeling leads to unnecessary avoidance of beta-lactams, use of non-optimal antibiotics, antimicrobial resistance, and increased healthcare costs. Beta-lactam allergy delabeling is mainly evaluated through the use of clinical databases. Patient perceptions, quality of life, and real-world barriers before and after delabeling remain insufficiently explored.

This cross-sectional questionnaire-based study included 96 adult patients with a reported history of beta-lactam hypersensitivity: 46 patients after successful specialist delabeling (POST) and 50 patients before specialist evaluation (PRE). Structured telephone interviews assessed diagnostic pathways, perceived correctness of diagnosis or exclusion, confidence in beta-lactam safety, antibiotic use, family attitudes, and recurrence of symptoms. Quality of life was evaluated using the WHO Quality of Life Breve Field (WHOQOL-BREF) questionnaire.

As expected, perceived safety of beta-lactam antibiotics was significantly higher in POST than in PRE (7.37 vs 2.40 on a 10-point scale; p < 0.001). WHOQOL-BREF scores were similar between groups (p > 0,05), except for a small difference in the Environment domain favoring POST (p = 0.029). Among POST patients, 57% (n = 26) required antibiotic therapy during follow-up; of these, 65% (n = 17) received beta-lactam antibiotics. Importantly, in 9 cases (35% of patients with an indication), beta-lactam antibiotics were withheld by physicians due to persistent doubts related to prior allergy labeling despite documented delabeling. Among patients re-exposed to beta-lactams, mild cutaneous symptoms occurred in 18% (n = 3), in 82% (n = 14); no side effects were reported, which confirms the result of delabeling. Cutaneous manifestations were the most common initial symptoms. Notably, 28% of POST patients reported continued family discouragement of beta-lactam use, and 50% of PRE patients declared they would refuse beta-lactams even after hypothetical allergy exclusion.

Beta-lactam allergy delabeling improves perceived safety and is associated with low recurrence rates upon re-exposure, though its impact on general quality of life is nonsignificant. However, persistent patient, family, and physician reluctance underscores the real-world effectiveness of delabeling.