Hundreds of millions of children worldwide are affected by allergies and other immunologic disorders. Pediatric allergy and immunology is a medical speciality that focuses on the diagnosis and treatment of children who suffer from allergies, asthma, eczema, and other immune system problems. Pediatric allergist-immunologists investigate the causes and triggers of children's illnesses, and they may utilise preventive and therapy measures to lessen the intensity and frequency of symptoms and reactions. Immune abnormalities in pediatric diseases, particularly those involving host defence mechanisms, have been the concern of pediatric immunologists. These efforts have yielded significant advances in immune system fundamentals as well as notable therapeutic breakthroughs. Bacterial, viral, parasite, or fungal infections of the stomach, intestines, respiratory system, ears, eyes, or skin, as well as sexually transmitted diseases, can all affect children. Children and adolescents with all types of infections, including pneumonia or meningitis, chronic and recurrent infections, HIV/AIDS, infections associated with international travel, post-surgical infections, and infections in children with suppressed immune systems, are treated by pediatric infectious disease specialists.