sicca syndrome

Sicca syndrome results from lymphocytic infiltration and destruction of exocrine glands, most classically the lacrimal and salivary glands, leading to decreased tear and saliva production. Patients present with dry eyes (foreign body sensation, decreased tear production measured by Schirmer test), dry mouth (dysphagia, dental caries, difficulty speaking), and sometimes parotid gland enlargement. It is most commonly associated with primary Sjögren syndrome, an autoimmune disorder predominantly affecting middle-aged women, characterized by anti-Ro/SSA and anti-La/SSB antibodies. Sjögren syndrome can be primary or secondary (associated with other autoimmune diseases like rheumatoid arthritis, SLE, or systemic sclerosis). Pathologically, there is focal lymphocytic sialadenitis on minor salivary gland (lip) biopsy, with CD4+ T cell predominant infiltration. Patients with Sjögren syndrome have an increased risk of non-Hodgkin lymphoma (particularly MALT lymphoma) of the salivary glands, so persistent unilateral parotid enlargement should raise suspicion for malignant transformation. Other complications include dental caries, esophageal dysmotility, and renal tubular acidosis (distal, type I). Diagnosis involves clinical symptoms, Schirmer test, anti-Ro/La antibodies, rheumatoid factor (often positive), ANA, and lip biopsy showing lymphocytic infiltration. Treatment is symptomatic: artificial tears, saliva substitutes, pilocarpine or cevimeline (muscarinic agonists) to stimulate secretions, and immunosuppressants for systemic involvement. Sicca symptoms can also occur in other conditions such as sarcoidosis, amyloidosis, IgG4-related disease, GVHD, and as a side effect of medications (anticholinergics) or radiation therapy to the head and neck.