In the past two months, two patients with Mikuliz disease were admitted to our department. Both patients were family members of doctors and had been misdiagnosed for 6 years, and had sought medical treatment in many hospitals in our city and province, but failed to make a clear diagnosis. The two patients were one of each sex. The male patient was the husband of a hospital director in Huixian, a teacher by profession, and the female was the sister of a doctor at Xinxiang Infectious Disease Hospital. The symptoms were swelling of both eyelids, swelling of parotid and submandibular glands, weakness, splenomegaly, lymph node enlargement, and elevated blood glucose. IgG4-associated disease is a chronic progressive autoimmune disease that can involve multiple organs and tissues and is characterized by elevated serum IgG4 and a significant proliferation of IgG4-secreting plasma cells in tissues, leading to fibrosis and sclerosis. The clinical spectrum of the disease is broad and includes a variety of diseases such as Mikuliz’s disease, autoimmune pancreatitis, interstitial pneumonia, interstitial nephritis, and retroperitoneal fibrosis. The characteristic pathological changes are sclerosis and fibrosis due to massive infiltration of lymphocytes and IgG4-positive plasma cells plasma cells in tissues and multiple organs. The disease is characterized by swelling and enlargement of one or more organs or tissues with sclerosis that resembles tumorigenicity, significantly increased serum IgG4 levels, and good response to glucocorticoid therapy. The commonly involved organs and tissues are pancreas, lacrimal gland, parotid gland, mandibular gland, salivary gland, retroperitoneal tissue, pituitary gland, and lung and kidney. Diagnostic criteria for Mikulisub disease: 1. symmetrical enlargement of at least 2 pairs of glands in the lacrimal, parotid and submandibular glands lasting at least 3 months; along with 2. elevated serum IgG4; or 3. histopathological features: lymphocytic and IgG4 plasma cell infiltration with typical tissue fibrosis or sclerosis. Clinical treatment revealed that IgG4-related disease responds well to hormonal therapy, with low to moderate doses of hormones resulting in a significant reduction in organ swelling, a decrease in serum IgG4, and a significant improvement in clinical signs and symptoms, with the addition of immunosuppressive drugs if necessary. In these two patients, the symptoms resolved rapidly after treatment, relieving them of the pain that had plagued them for years.