Contrast-Induced Sialadenitis: An Under-Recognized Adverse Reaction in Radiology and Clinical Practice

Contrast-induced sialadenitis (CIS), a rare inflammatory reaction of the salivary glands, occurs after exposure to iodinated contrast media (ICM). This self-limiting condition typically manifests as glandular swelling and pain, with variable severity, from hours to days post-contrast administration. Its etiology includes inflammatory edema, ductal obstruction, and pseudoallergic or idiosyncratic reactions. Non-ionic, low-osmolar agents such as Iohexol and Iodixanol are frequently implicated. Risk factors include iodine allergy, renal dysfunction, and inadequate premedication. Diagnostic imaging via CT or ultrasound reveals characteristic findings such as glandular enlargement, periglandular fat stranding, and heterogeneous enhancement, aiding differentiation from other causes like infection or neoplasms. This case series presents three patients who developed sialadenitis following contrast-enhanced CT scans. Presentations ranged from mild, localized submandibular swelling to rapid-onset bilateral glandular inflammation involving the parotid and submandibular glands. All cases highlight the need for prompt recognition and adherence to preventive measures, including premedication with corticosteroids and hydration, especially in high-risk patients. Management is largely supportive, involving corticosteroids, antihistamines, and NSAIDs, with severe cases requiring closer monitoring. By raising awareness of this underreported condition, this article underscores the importance of early recognition and differentiation from other conditions by radiologists, emphasizing their role in timely diagnosis and management. It also calls for further research to optimize prevention and management strategies.