Many tickborne diseases can have similar signs and symptoms. When to Worry About a Rash in Adults? ; Although hives are very common, their cause is often elusive. Hives can change size rapidly and move around, disappearing in one place and reappearing in other places, often in a matter of hours. It may be the result of infection, a chronic skin condition, or contact with an allergen or irritant. Skin rash is a common symptom in children and adults, but it is definitely more common in children. However, hives are more often irregular in shape and can join together in larger patches, especially if you scratch them. If you have been bitten by a tick and develop the symptoms below within a few weeks, a health care provider should evaluate the following before deciding on a course of treatment: Hives tend to fade within 24 hours, although they may be noticeable for several days or longer. Chronic hives — Chronic hives occur daily or almost daily and last longer than six weeks, sometimes for years. These illnesses are usually viruses, but can be any cause. Most individual hives fade quickly, but new crops may appear every 24 to 72 hours if the person continues to be exposed to the environment or substance that triggered the hives. So, if your child is sick, and breaks out in hives, it is probably due to the illness. A note – don’t worry about what illness might be causing the hives. Illness – illnesses are the most common cause of hives in children. Stress hives can look a little like bug bites: both are red, puffy, and itchy, and may appear initially as individual bumps, says Stevenson. A bad case of hives may appear as a single large patch of puffy, raised skin. Hives can be triggered by some food additives, including artificial colors, flavoring agents, and preservatives, according to research published in June 2013 in the Indian Journal of Dermatology. Hives … Is your skin itching, breaking out, covered in a rash, or playing host to spots of some sort? The medical name for hives is urticaria. Other symptoms to note: Hives are most of often the result of exposure to allergens, and they could be a sign of a serious allergic reaction. Hives (medically known as urticaria) are red, itchy, raised welts on the skin that appear in varying shapes and sizes; each one characteristically lasts no longer than six to 12 hours. Chickenpox and erythema infectiosum are common in children, and patients with these infections have a characteristic skin rash, but … Hives affect how you look, and people may worry about being near you for fear that you have a contagious infection. Common signs and symptoms of penicillin allergy include hives, rash and itching. Sometimes, the welts from hives join together to form larger areas called plaques. Hives may be itchy, or you might feel them burning or stinging. Hives can affect skin on any area of the body, especially the trunk, thighs, upper arms and face. The body can have an allergic reaction to the illness. Severe reactions include anaphylaxis, a life-threatening condition that affects multiple body systems. An allergic reaction becomes more serious and is considered a medical emergency when any of the signs or symptoms are particularly severe, such … Hives vary in size, and some may blend to form larger areas of swelling. Chronic hives can be frustrating because they come and go and can interfere with sleep, work, or school. They can be as small as a pinprick or as big as a dinner plate.