It is possible to apply a mask externally after an allergy on the face, but a high degree of attention should be paid to the choice of the mask, which is directly different from the mask that the patient usually applies at this time. When the face is allergic, in fact, the external mask mainly plays a role in keeping the skin moist, and it must be very simple and safe ingredients to use. Clinically, patients can generally be advised to apply hyaluronic acid repair biofilm for external application, and at the same time can be applied with antihistamines, or directly apply blue skin spray on sterile mask paper to the face, which can also play an effective role in keeping the skin moist. Direct application of sterile saline sprayed onto mask paper or dipped onto sterile gauze and applied to the face can also play a moisturizing role.