Children with redness, swelling and hard lumps on the soles of their feet may be related to mosquito bites, local trauma, frostbite and other factors. 1. Mosquito bites: generally occur in the hot summer, especially mosquitoes are more places, in the small children’s feet by mosquito bites, may be due to local metamorphosis produced by the phenomenon of redness, swelling, hard lumps, accompanied by symptoms of itching, and mosquito bites into the child’s body to inject trace toxins related. 2. Local trauma: some small children may be due to collision, accidentally stuck to the nail, resulting in localized redness, swelling and hardness of the symptoms, which belongs to the skin soft tissue inflammation caused by the injury. 3. Frostbite: generally occurs in the cold winter, usually because of excessive cold, resulting in limited bruising skin inflammation damage, and then there will be redness and swelling of the soles of the feet. Children with red, swollen and hard lumps on the soles of the feet, there may also be other causes, if necessary, with the doctor to improve the examination to determine the cause and then do treatment and treatment.