Children are particularly prone to rashes that develop as a result of illnesses, such as: chickenpox, which is a virus characterized by red, itchy blisters that form all over the body measles, which is a viral respiratory infection that causes a widespread rash consisting of itchy, red bumps scarlet fever, which is an infection due to group A Streptococcus bacteria that produces a toxin causing a bright red sandpaper-like rash hand, foot, and mouth disease, which is a viral infection that can cause red lesions on the mouth and a rash on the hands and feet fifth disease, which is a viral infection that causes a red, flat rash on the cheeks, upper arms, and legs Kawasaki disease, which is a rare but serious illness that triggers a rash and fever in the early stages and can lead to an aneurysm of the coronary artery as a complication impetigo, which is a contagious bacterial infection that causes an itchy, crusty rash and yellow, fluid-filled sores on the face, neck, and hands. You can treat most contact rashes, but it depends on the cause. Follow these guidelines to help ease discomfort and speed up the healing process: Use mild, gentle cleansers instead of scented bar soaps. Use warm water instead of hot water for washing your skin and hair. Pat the rash dry instead of rubbing it. Let the rash breathe. If it’s possible, avoid covering it with clothing. if,child feels low energy complain then give him balance diet.avoid oily and unhealthy food.give him fruit juices and liquid intake more. use filtered and boiled water to avoid further infection by any other bacteria or virus.