Toddler Foot Rash Symptoms, Causes, and Treatment. It is very common for a toddler’s body to break into rashes. There are common problems like impetigo, eczema, or dermatitis that can affect the legs, hands, face, and other body parts of your child. Toddler rash on the legs is however particularly common. These rashes may sometimes be difficult to treat, especially because a toddler’s skin is sensitive.