How do you approach a child with recurrent parotitis who has had negative serum testing for Sjogren's and IgG4 related disease?

Minor salivary gland biopsy is pretty random and subjective; finding >50 lymphocytes per set field is not that specific/helpful. I would think a parotid gland biopsy and extensive work-up (TB, HIV, sarcoid, lymphoma, etc.) is in order.