(Disclaimer: This article is for scientific use only. To protect patient privacy, the information in the following content has been processed.) Abstract: Food allergy can manifest itself as flushing and itching, sneezing, and tightening of the throat minutes after eating, or as gastrointestinal symptoms such as abdominal pain, diarrhea, and vomiting several hours later, or even as skin symptoms such as eczema and itching several days later. In this case, the child’s food allergy manifested itself in a delayed manner, and the child’s symptoms were effectively relieved after allergen testing and corresponding medication. [Basic information] Female, 2 years old [Disease type] Food allergy [Hospital] Wuhan University Central South Hospital [Consultation date] August 2021 [Treatment plan] Allergen examination + allergen avoidance + medication (probiotics + vitamin E cream + topical glucocorticoids) + food diary [Treatment cycle] Outpatient recheck of allergen after half a year [Treatment effect] The child did not have any more gastrointestinal symptoms, and the allergic symptoms were effectively controlled. The child came to our department with recurrent head, neck and limb eczema. The child’s mother was very anxious and complained that the child had a perioral erythematous papule when he was about half a year old, which gradually spread to the neck behind the ear, and in severe cases, erythema and papules were also seen on the skin of the joints of the limbs. At the age of 1 year, the child’s blood was tested positive for specific IgG at an outside hospital, and he was tested positive for various allergens using bioresonance. He was told that he was allergic to milk, beef, chicken, freshwater fish, tomatoes, shrimps and crabs, walnuts and noodles, and was advised to avoid all of the above foods and food-related products; he was also told that he was allergic to dust mites, cotton wool, various pollens and fungi, and was advised to keep his house clean and hygienic. The child’s family followed the medical advice for almost 7 months, but not only the symptoms of eczema, blood in stool and abdominal pain did not improve, but also the developmental delay was observed. During the illness, the child had been free of eye, nose, and lower respiratory tract mucosal symptoms. After detailed medical history, the child was given allergen skin test and serum specific IgE test. The results were significantly different from those of the external examination 8 months ago, except for the dust mite skin test of ++ and dust mite serum specific IgE of grade 2, and the egg white skin prick of ++ and egg serum specific IgE of grade 3, which were all negative. Considering that the child had no nasal, ocular or bronchial mucosal symptoms, only dust mite sensitization was diagnosed at this stage. The child’s allergen type was clear through the allergen skin test, and the food diary for 4 weeks after avoiding eggs and their products showed that each abdominal pain was associated with the consumption of peanuts 5-6 hours before, so it was recommended to further avoid peanut products. After good and effective communication, the child was given probiotics + vitamin E cream + topical glucocorticoids with the consent of the child and his family, and his family was advised to take the child to outdoor activities more often and avoid over-sterilization of clothes, and to review the allergens in six months. In addition, the child’s family was advised that egg allergy usually resolves spontaneously with age, but peanut allergy may be a lifelong condition. Treatment effect Through food diary treatment and probiotics + vitamin E cream + topical glucocorticoids, the child’s digestive tract and skin allergy symptoms were effectively relieved. The skin of the child’s neck and joints of the extremities were significantly better than before. The results of the allergen review after 6 months were also very promising. The child’s family indicated that after more than 1 year of strict avoidance of eggs and peanut products as prescribed by the doctor, no more abdominal pain after eating or blood in the stool occurred, but the perioral eczema still recurred when the child had a cold. Since the child has not been fasted from other foods, adequate nutrition can be ensured, so the child’s weight and height have improved significantly, and the anxiety of the child’s family has basically disappeared. This child was temporarily sensitized only by dust mites and did not show allergy. It is necessary to review the allergen in another 6 months to 1 year to observe whether dust mite allergy or tolerance occurs. Food allergy is an important factor in the recurrence of atopic dermatitis, but destruction of skin barrier function, massive release of skin inflammatory factors, and dysbiosis of microecological flora are also causes of atopic dermatitis, so topical glucocorticoids should be seen to provide an artificial skin barrier by insisting on the use of vitamin E cream. From the point of view of hygienic doctrine, it is recommended that the affected child be more active outdoors and avoid over-sterilization of clothing. For food allergy, pay attention to avoiding allergens in diet to prevent recurrence. If the corresponding symptoms appear again, please consult the doctor promptly and treat symptomatically under the guidance of the doctor. V. Personal insight Professional testing methods and testing instruments for allergic reactions are mixed. Food-specific IgG is not a diagnostic indicator of food intolerance, much less food allergy, but only an indicator that we have eaten these foods. The current food allergy test can only be used for rapid reactions, but there is no good way to diagnose other types of food allergies, and the food diary is an effective way to diagnose the presence of food allergies. If you have a food allergy reaction, you should seek medical attention, identify the allergen under the guidance of a doctor, and treat the symptoms, and avoid such allergic substances in your daily life to avoid recurrence.