Spring is the season of allergy. Many babies tend to suffer from allergy or aggravate allergy in spring, why is that? What can be done about it? Immune function is the body’s innate ability to defend itself against invading viruses and germs. Our eyelashes, nose hairs, mucous membranes of the respiratory tract and skin are the first line of defense, acting as a barrier to entry. Immune cells such as white blood cells in our body are the second line of defense and they produce antibodies to fight against the invasion of harmful substances. Sneezing and coughing, like when you have a cold, is a manifestation of the immune response. Although the body is protected by the immune function, sometimes it can make small mistakes. When the immune function treats harmless substances from the air, water, food, etc. as “bad elements” to defend against, this overreaction can cause the body to develop allergies. This is why many babies are allergic to milk and eggs. Allergic reactions are called allergies or atopic reactions and have a genetic relationship. There is no very effective treatment for allergies, and the most important thing is to be proactive in prevention. Allergies can change over time. Initially, skin allergy may occur, but after a longer period of time, allergy can attack the respiratory tract and evolve into allergic rhinitis, allergic cough and allergic asthma, which become more difficult to treat. There are many allergens in life, which are very common for non-allergic people, but may be a potential “threat” for those who are allergic. The typical substances that cause allergies are dust, dust mites, mold, pollen, animal fur, food, odors, etc. Although the temperature is rising, the temperature difference between morning and evening is still relatively large, and the difference between indoor and outdoor temperatures is also significant. The baby’s skin is delicate and has a poor ability to resist external aggressions, so when it encounters cold wind stimulation it can easily lead to skin allergies. In addition, dry air and low humidity can also reduce the barrier function of the nasal mucosa and lead to inhalation allergic reactions. The symptoms of allergy are similar to those of many common diseases, so it is easy to ignore or treat them as other diseases, which can easily delay the best treatment of allergy and lead to more serious allergy. Allergic babies may show flushing of the cheeks, nose and earlobes, wetness in the ear canal, earache, nasal congestion, sneezing, dark circles under the eyes, swollen and droopy eyelids, headache, dry lips, dry or sweaty skin, wrinkles in the corners of the eyes or palms, abdominal pain, diarrhea, bloating, constipation, eczema on the arms, legs or joints, and recurrent infections. Skin changes and other allergic phenomena are easy to detect, but I do not know that sometimes the abnormal performance of babies is also caused by allergies, such as babies are easily irritable, cry, and even have a love of biting and hitting; babies often rub their eyes, like to blink; often shrug their noses, pick their noses, dry cough; difficulty sleeping, easy to sweat; stuttering, fast heart rhythm, inattentiveness and hyperactivity may also be caused by allergies. Allergy symptoms will continue to change and must be taken seriously. As babies grow up, some allergy symptoms will slowly reduce or disappear, but this is not the same as saying that allergies can be left alone. If allergic diseases are not controlled in time, they can easily turn into chronic diseases such as asthma, and in serious cases, they can affect the baby’s intelligence and physical development. If allergies are not dealt with in a timely manner at the beginning, the symptoms will continue to develop and worsen, making it difficult to cure allergies, but it is not true that all allergies are incurable. For allergies, the most important thing is to find the allergen in time, decisively avoid the allergen, and with reasonable treatment, some allergies in infancy and early childhood can be cured. The key to a cure is whether the allergen can be completely interrupted and maintained for at least 6 months. Babies with frequent colds and recurrent fever and cough are likely to be caused by allergies rather than the common cold. Instead of being caused by a low immune system, allergies are a sign of an abnormally strong immune system. The cause can be determined through allergen testing. Do not use immune boosters easily, as this will instead make the allergy more severe. If your baby is allergic, you can add complementary foods a little later: Generally, babies can start to add complementary foods 4-6 months after birth, if your baby is allergic, you can add complementary foods a little later, but at the latest at the end of 6 months. Infancy is the fastest growing baby, if you add complementary foods too late to avoid allergies, resulting in malnutrition and developmental delays, it is not worth the loss. As long as you follow the principles of complementary foods and avoid adding allergy-prone foods too early, you can.