Salivary Gland IRIS — SCE Infectious Diseases MCQ

Correct answer: E — Salivary gland IRIS — immune reconstitution causing inflammation of previously subclinically affected parotid glands

The most likely diagnosis is salivary gland immune reconstitution inflammatory syndrome (IRIS). She has advanced HIV, has started ART recently, and has had a marked fall in viral load, followed within 3 weeks by a new inflammatory presentation in a site that may have been subclinically affected by HIV-associated salivary gland disease. This pattern is classic for unmasking IRIS: restoration of immune responses after ART produces inflammation and clinical disease that was not apparent before treatment. Bilateral painful parotid swelling with xerostomia is therefore best explained by immune reconstitution involving the parotid/salivary glands. Parotid lymphoma would usually be a mass or progressive asymmetric enlargement rather than an acute bilateral inflammatory syndrome temporally linked to ART response. Sjögren syndrome causes chronic sicca symptoms and autoimmune features, not an acute post-ART presentation. Mumps can cause bilateral parotitis but would usually have an infectious prodrome/exposure context and is not specifically linked to rapid HIV viral-load decline. Dehydration-related sialadenitis is usually associated with systemic dehydration and does not explain the ART timing and virological response.

Reference: British HIV Association (BHIVA). BHIVA guidelines for the management of tuberculosis in adults living with HIV, 2024 — IRIS definition: unmasking of occult disease after ART and appearance of new inflammatory signs/symptoms after ART initiation. https://bhiva.org/wp-content/uploads/2024/10/BHIVA-TB-guidelines.pdf