O20 Approach to parotid swelling

Abstract Case report - Introduction The rarity of paediatric salivary gland disease and the lack of pathognomonic signs are likely to contribute to delay in diagnosis and make a structured approach to parotid swelling particularly important. Here we discuss a case of a 4-year-old girl with recurrent parotid swelling and some features to suggest multisystem involvement. Case report - Case description A partially immunised, 4-year-old girl with a history of eczema and vitiligo presented with a 3-month history of intermittent painless pre-auricular swelling. She had 2 days of fever at onset but was otherwise afebrile. She reported intermittent joint pain without swelling. There was no cough, coryza, sore throat, dryness of the mouth or eyes, rash, systemic upset, and no other evidence of multisystem involvement on systems review. She had no unwell contacts and no family history of autoimmune disease. On examination she had bilateral pre-auricular swelling which was non-tender, not fluctuant, and had no overlying skin changes. No calculi were identified on bimanual palpation of the parotid ducts and no pus was visible at the opening. Respiratory, cardiovascular, abdominal, musculoskeletal, and skin examination were unremarkable. Her bloods showed microcytic anaemia, raised ESR (peak 97mm/hr), CRP (peak 30mg/l), CK (peak 628 IU/l), and LDH (peak 512 IU/l), but normal ferritin and ACE. Serology showed ANA 1/10240, RNP Ab positive, negative myositis specific ENA, dsDNA, and rheumatoid factor, and normal complement. Infection screen, including TSpot, and screening for immunodeficiency were negative. Her urine dipstick was normal. Interferon signature was abnormal with very high levels. Parotid ultrasound scan showed heterogenous enlargement of all major salivary glands and lacrimal glands with reactive cervical lymph nodes. CT chest demonstrated basal ground-glass change and hilar, mediastinal, and axillary lymphadenopathy. Parotid biopsy was normal on two occasions, with no evidence of lymphoma or granulomatous disease. At this stage she was treated for undifferentiated autoimmune connective tissue disease with steroids and mycophenolate mofetil. Due to the lack of improvement and persistently mildly elevated CK and LDH, MRI thighs was subsequently performed. This demonstrated mild myositis prompting a muscle biopsy which showed typical features of juvenile dermatomyositis. She was therefore commenced on intravenous immunoglobulin and subcutaneous methotrexate. C