Allergy History and Psychiatric Diagnoses as Predictors of Postoperative Outcomes in Headache Surgery

Polyallergy, a condition characterized by multiple non-immune-mediated reactions, has been associated with somatic symptom disorder (SSD), a psychiatric diagnosis characterized by excessive anxiety and preoccupation with physical symptoms without objective physical findings. SSD has been linked to a higher incidence of migraines and poorer surgical outcomes. Given these associations, this study examined whether polyallergy could serve as a preoperative marker for predicting outcomes after headache surgery involving peripheral nerve decompression.

A retrospective cohort study was conducted of patients who underwent headache surgery between 2012 and 2017 with a single plastic surgeon. Patient-reported outcomes assessed with the Headache Impact Test-6, Migraine-Specific Quality of Life Questionnaire, and Migraine Disability Assessment; psychiatric diagnoses; and allergy history were collected. Polyallergy was defined as 2 or more allergies without immune-mediated confirmation or anaphylaxis. Subgroup analyses were performed based on polyallergy and psychiatric history.

Patients with polyallergy experienced significantly less improvement in Headache Impact Test-6 (11.9% versus 56.3%; P = 0.002) and Migraine Disability Assessment (29.8% versus 93.7%; P = 0.010) scores, with Migraine-Specific Quality of Life Questionnaire scores approaching significance (44.0% versus 138.0%; P = 0.056). Polyallergy was associated with a roughly 50% to 70% lower likelihood of achieving clinically significant improvement. Patients with an anxiety disorder had less improvement, but the differences were not statistically significant. There were no differences in improvement between those with or without a mood disorder.

Polyallergy is associated with poorer outcomes after headache surgery and may serve as a chart-accessible marker to identify individuals at risk for suboptimal improvement. These findings offer a novel application of polyallergy as a behavioral proxy for SSD in migraine surgical care and may aid patient selection and preoperative counseling.