Lactose intolerance generally does not cause eczema in patients. Lactose intolerance can be divided into primary lactase deficiency, secondary lactase deficiency, and congenital lactase deficiency. Patients with lactose intolerance mainly experience symptoms such as abdominal pain, diarrhea, nausea, vomiting, increased bowel sounds, intestinal colic, and bloating. Some patients experience reduced intestinal motility, leading to constipation, and the severity of symptoms is related to the amount of dairy products consumed. Therefore, a small number of patients can tolerate a certain amount of dairy products without experiencing significant symptoms, and the specific tolerable amount varies from person to person.