Dry mouth and eyes is a common manifestation of dry syndrome (hereinafter referred to as SS), but some patients do not have the complaint of dry mouth and eyes, or even if they have it, it is often ignored, but some non-specific symptoms and signs, such as joint pain, Raynaud’s phenomenon, recurrent parotid enlargement, multiple caries, unexplained hyperglobulinemia, etc., are the main complaints, which is very easy to cause missed diagnosis or misdiagnosis, and can be called atypical SS. According to the literature It is reported that only 50-60% of the diagnosed cases of SS have dry mouth and eyes as the main complaint, and it usually takes 8-10 years from the appearance of the first symptom to the final diagnosis. Early on, dry mouth and eyes may not necessarily appear because the exocrine glands are not severely damaged or the patients are not sensitive to the symptoms. The following are several diseases that are more likely to be clinically confused with SS or misdiagnosed: 1. Misdiagnosis of rheumatoid arthritis due to joint pain with positive rheumatoid factor: 70% of SS can manifest as non-erosive arthritis with symptoms of joint pain or joint swelling, plus it is often accompanied by positive rheumatoid factor and elevated blood sedimentation, so it is easily confused with rheumatoid arthritis. Rheumatoid factor is not specific for the diagnosis of rheumatoid arthritis and can be found in a variety of connective tissue diseases. If joint pain with positive rheumatoid factor is accompanied by the presence of anti-SSA and/or anti-SSB antibodies, the possibility of SS should be considered. Corresponding dry mouth and eye examination is required to help reduce misdiagnosis. 2. Misdiagnosis of SS as SLE due to positive anti-nuclear antibody: SS often has positive serum ANA antibody, and a few may also have dsDNA antibody, together with arthralgia, fever, rash, hematocrit, etc., so it is easily misdiagnosed as systemic lupus erythematosus (SLE). However, there is no evidence of systemic damage in SS, and there is often a history of dry mouth and flaky loss of teeth and recurrent enlargement of parotid glands upon careful questioning. 3. Misdiagnosis as allergic purpura due to purpura-like rash on the lower extremities: 30% of SS patients can have recurrent skin purpura or purpura-like rash, especially on the lower extremities, mainly caused by increased vascular fragility and enhanced permeability due to hyperglobulinemia. If it occurs before the onset of dry mouth and eyes symptoms, it can be easily misdiagnosed as allergic purpura. Therefore, when patients complain of purpura-like rash, the possibility of SS should be thought of. 4. Misdiagnosis of chronic hepatitis due to hyperglobulinemia and abnormal liver function: about 90% of SS patients have hyperglobulinemia, which causes elevated gamma globulin and inverted albumin ratio, and is easily mistaken for cirrhosis; in addition, 20% of SS itself can have liver damage and abnormal liver function, thus showing symptoms of chronic hepatitis, jaundice or hepatosplenomegaly, so long-term misdiagnosis as chronic viral hepatitis and Therefore, long-term misdiagnosis as chronic viral hepatitis and liver cirrhosis is not uncommon. 5. Misdiagnosis as respiratory disease due to recurrent cough and wheezing: SS can involve reduced secretion of glands in the respiratory tract, resulting in dry nasal cavity, hoarseness, irritating dry cough, thick sputum, wheezing, hemoptysis, wet rales in the lungs and other symptoms and signs, which are easily complicated by bronchitis, interstitial pneumonia and other diseases. It is often misdiagnosed clinically as bronchitis, interstitial pneumonia, bronchiectasis, etc. 6. Misdiagnosis of anemia, leukocyte and thrombocytopenia as hematologic diseases: about 24% of SS patients have anemia, 18% and 14% of leukocyte and thrombocytopenia, respectively. Among them, thrombocytopenia is easily misdiagnosed as thrombocytopenic purpura; fever with enlarged liver, spleen and lymph nodes is easily misdiagnosed as lymphoma and lymphadenitis; whole blood cell reduction is misdiagnosed as aplastic anemia and myelodysplastic syndrome; weakness and low hematocrit are misdiagnosed as iron deficiency anemia, etc. The incidence of SS is the first among connective tissue diseases. For those who have unexplained hyperglobulinemia, rampant dental caries, mucous discharge from eye canthus, long-term ocular foreign body sensation, recurrent swelling of parotid gland, arthralgia, unexplained long-term diarrhea, and all patients with proposed rheumatism, they should be routinely asked whether they have symptoms of dry mouth and eyes. Because atrophic gastritis, autoimmune hepatitis, primary biliary cirrhosis, and renal tubular acidosis are often secondary to or combined with SS, patients with the above diseases should be examined for ANA, anti-SSA antibody, anti-SSB antibody, and other indices in addition to asking whether they have symptoms of dry mouth and eyes, and if necessary, oral ophthalmology consultation should be requested to assist in the diagnosis in order to improve the diagnosis rate of the disease.