Hives can affect anyone, with between 10 and 25 percent of people getting them at least once in their lifetime, states the Children's Hospital-Denver. This type of rash is characterized by pink or red, slightly raised bumps that are typically itchy. Hives are quite common in children and are due to the body's production of histamine, an immune defense, in response to illness or exposure to various irritants. Histamine causes various responses that work to fight off the offending agent.
Body and Environmental Temperature
Extreme temperatures can trigger hives, according to MedlinePlus. Both cold and hot environmental temperatures can have a similar effect on children. Direct sunlight, large quantities of perspiration and even emotional duress can result in the development of this itchy rash states the Children's Hospital-Denver. Once the child's body is allowed to return to a normal body temperature, the rash will likely disappear.
Allergens
Allergens come in many forms, ranging from edible types to environmental types. Children may have temporary allergies that cause hives or the reaction can be lifelong. Common environmental allergens include pollen from trees, pet dander and mold. Similar to the pollenating tree, some fruits, including strawberries, set off child hay fever. Other edible allergens include nuts, shellfish, eggs and milk. When hives are accompanied by other allergic responses, such as wheezing or trouble breathing, the child requires medical attention. It is best to assume that once a child has this type of reaction that it will happen with future exposure as well. A portable pen may be prescribed by a doctor to inject the child with adrenaline to help reduce the severity of the reaction until medical care can be provided.
Illnesses
Some illnesses, including bacterial or viral infections, can cause hives on a child's body, states MedlinePlus. In addition to the illness, a child may have an allergic reaction to medications used to treat an illness. Antibiotic use can cause a mild rash on a child's body, which is different from hives. Any rash following medication use should be discussed with a health care professional. Serious allergic reactions to medications can be deadly and can be recognized by trouble breathing, a sudden drop in blood pressure and any other unusual bodily reaction that accompanies the hives.
Other Irritants
Whether a child has a true allergy to certain agents or just a sensitivity the body may produce histamine to protect itself from the irritant it perceives as harmful. This can include irritants like detergents, perfumes, dyes and even some textiles like wool. AskDrSears.com suggests that soaps, shampoos, fabric softener and even exposure to grass or outdoor objects can cause hives without the child having an actual allergy.
