Background: Edema of the uvula (EU) may appear in isolation or in association with clinical manifestations such as urticaria, angioedema, and anaphylaxis. EU may lead to upper airway obstruction, provoking obstructive respiratory distress and asphyxia.
Objective: We sought to investigate the etiology of and predisposing factors for EU in a large population of patients referred to an outpatient clinic.
Methods: In this 3-year follow-up cohort study, 171 patients presenting with EU were identified and classified as having isolated EU or nonisolated EU. The etiology of each patient’s condition was studied, and possible predisposing factors were recorded. An allergology work-up and a statistical study (bivariate/multivariate analyses) were performed.
Results: The predisposing factors for both groups of EU patients were found to be different. The etiology of the problem was identified for most patients; allergy to Anisakis simplex was the most common cause in both groups. Nonsteroidal anti-inflammatory drugs and antibiotics were also found to be triggers in both groups.
Conclusions: Isolated EU was associated with snoring, an elongated uvula, and having experienced previous episodes of EU. We found no associations between groups of EU patients and gender, obesity, smoking, alcohol consumption, personal and family history of atopy, and obstructive sleep apnea. Allergy to A simplex was the most commonly recorded cause.

Key words: Allergy, Anisakis simplex, Elongated uvula, Obesity, Smoking, Snoring, Uvula edema