Hives, known medically as urticaria, are a common skin reaction characterized by raised, itchy welts that can appear anywhere on a child’s body. These welts occur when the body releases histamine, a chemical that causes small blood vessels to leak fluid into the skin, leading to swelling and redness. Hives are frequent during childhood, with up to 20% of people experiencing an episode. Understanding the difference between a mild, temporary reaction and a medical emergency is important for proper care.
Common Causes and Presentations of Acute Hives
Most cases of hives in children are acute, meaning they are short-lived and resolve quickly, often within a few days or weeks. The most frequent trigger is a minor viral infection, such as a common cold, which accounts for up to 40% of cases. The immune response releases histamine, causing the skin reaction. Hives caused by infection are often a benign, self-limiting event.
Individual welts are typically transient, meaning they may disappear from one location and reappear in another spot within 24 hours. Other common, non-threatening triggers include insect bites or stings, mild food sensitivities, and contact with irritants like certain soaps or detergents. The defining feature of a typical acute reaction is its temporary nature.
Emergency Symptoms Requiring Immediate Care
The most serious concern related to hives is the potential for anaphylaxis, a severe allergic reaction that affects multiple body systems. If hives appear alongside signs of a systemic reaction, call emergency services or go to the nearest emergency room immediately, regardless of the rash’s severity.
Airway and Breathing Issues
These symptoms signal swelling in the throat or lungs.
- Persistent coughing or wheezing.
- A change in voice or difficulty swallowing.
- A high-pitched, noisy breathing sound called stridor.
- Swelling that affects the tongue, lips, or throat (angioedema), which indicates the airway may be compromised.
Systemic and Circulatory Issues
These indicate the reaction is affecting blood pressure and organ function. Watch for sudden dizziness, feeling weak, fainting, or becoming pale and floppy, especially in younger children. Gastrointestinal distress, including severe vomiting, abdominal pain, or diarrhea, can also be a component of a life-threatening reaction.
When Hives Become a Chronic Concern
Hives that occur almost daily for six weeks or longer are defined as chronic urticaria. While these are rarely a sign of immediate danger, they require consultation with a healthcare provider, such as a pediatrician or allergist, for investigation and long-term management.
In chronic cases, the cause is often not an allergy but is frequently classified as spontaneous, meaning no external trigger is identified. Less common causes include autoimmune conditions, such as thyroid disease, or a reaction to a chronic underlying infection. Physical triggers can also cause chronic inducible urticaria, with symptoms appearing in response to cold, heat, pressure, or exercise.
At-Home Comfort Measures
For mild, non-emergency cases of hives, the primary goal is to manage itching and discomfort. Applying a cool compress or a washcloth wrapped around frozen vegetables to the affected area can help constrict blood vessels and reduce swelling. Lukewarm baths, sometimes with the addition of colloidal oatmeal, can also provide soothing relief.
Avoiding irritants is another practical measure, which involves dressing the child in loose-fitting clothing and steering clear of harsh soaps or detergents that can exacerbate itching. Over-the-counter oral antihistamines, such as cetirizine or diphenhydramine, are the primary medication used to block the histamine causing the reaction. They are effective in controlling the itch and the spread of new welts.
Parents should always consult their pediatrician for the correct dosage of any over-the-counter antihistamine. Dosing for children is determined by weight and age, and relying solely on general packaging instructions can be unsafe. A healthcare provider can recommend the appropriate non-sedating antihistamine for daytime use and advise on a sedating option for nighttime relief if necessary.