Hives are a common skin reaction in children, characterized by a raised, flat pink rash called wheals and are most often caused by allergies1. Certain foods can trigger them, as can insect bites or some medication. In winter some children can even develop hives when they are exposed to cold air1.
We asked Dr Tamatha Urquhart, a Paediatrician, from Faerie Glen in Pretoria who specializes in allergies, all about hives, what causes them and how to treat them.
“Hives can appear anywhere on the body, including the face, lips, tongue, throat or ears,” she says. “They may change shape, move around, disappear and reappear over short periods of time”2.
The medical term for hives is urticaria. When a person is exposed to something that can trigger hives, certain cells in the body release a substance called histamine. This causes fluid to leak from the small blood vessels under the skin. When this fluid collects under the skin, it forms the blotches, which we call hives3.
“They vary in size from a few millimetres to several centimetres and may join together to form larger areas. They can last for hours, or up to one day before fading,” explains Dr Urquhart2.
The most common causes are certain foods, medications, or infections. “The most common foods that cause hives are nuts, fish, tomatoes, eggs and dairy. Certain food additives and preservatives also play a big role,” Dr Urquhart says and adds that it is sometimes difficult to find out exactly why hives have formed2.
In terms of classification, urticaria can be classified as acute or chronic based on the duration of illness. “Hives lasting less than six weeks are called acute urticaria. Hives lasting more than six weeks are called chronic urticaria,” Dr Urquhart explains and says that the cause of chronic urticaria is usually more difficult to identify than those causing acute urticaria. In fact, for many people with chronic urticaria, the cause is sometimes impossible to determine. “In some cases, the cause may be autoimmune diseases or reactions, chronic infections or food additives and preservatives,” she says2.
Another cause of urticaria is called physical urticaria where hives are caused by direct physical stimulation of the skin — for example, cold, heat, sun exposure, vibration, pressure, sweating, and exercise. The hives usually occur right where the skin was stimulated and rarely appear elsewhere2.
“It is difficult to determine the exact prevalence of childhood urticaria due to lack of population-based studies. In my practice, I find acute urticaria to be more common in children than chronic or physical urticaria,” she says2.
According to the European Medical Journal, the frequency of urticaria (acute and chronic) in children is about 2.1–6.7%4.
Hives usually cause itching, but may also burn or sting5. While some cases can be mild1; urticaria can also be severely debilitating6.
According to Dr Urquhart, infection, especially a viral infection, is the most frequently documented cause of acute urticaria in children, responsible for up to 40% of cases2.
If a child’s hives last for more than a month, Dr Urquhart suggests that you make an appointment to see an allergist, who will take a history and perform a thorough physical exam to determine the cause of your child’s symptoms2.
Therapies range from prescription antihistamines and other drugs, such as anti-inflammatory medications and medications that may modify your immune system2.
“In some cases, the trigger is obvious – a person eats peanuts or shrimp, and then breaks out within a short time,” she says. Other cases require detective work by the patient, parent and the physician because there are many possible causes. “In a few cases, the cause cannot be identified,” she says2.
Dr Urquhart says that a single episode of hives does not usually call for extensive testing. If a food allergy is suspected, consider keeping track of what your child eats. This will help you discover whether there is a link between what they are eating and when they break out with hives. If the cause of hives can be identified, the best treatment is to avoid the trigger or eliminate it2.
In mild cases of hives, your doctor may determine that no treatment is required. However, to make a child less itchy and more comfortable, the doctor might suggest an oral antihistamine1. Less often, hives can be a sign of a more serious allergic reaction that can affect breathing and other body functions. In these cases, the person needs immediate medical care3.
Antihistamines – available either over the counter or by prescription – are a frequently recommended treatment for hives. “They work by blocking the effect of histamine. Non-sedating antihistamines are preferred. They are effective and long-lasting (may be taken once a day), are safe and have few side effects”, Dr Urquhart says. In chronic urticaria, antihistamines usually need to be taken daily for at least 6 months and sometimes up to 2 years or longer in more severe cases2. Serious episodes of urticaria may require more serious treatment regimes2.
Furthermore, treatments for allergies that not only inhibit histamine, but also a substance called Platelet-activating factor (PAF), are today being recognized as more effective in providing relief for urticaria7. PAF is a molecule which also causes an inflammatory reaction when exposed to an allergen8.
Speak to your doctor or pharmacist about a second generation antihistamine, which is non drowsy and provides 24 hour relief, suitable for children over the age of 129. This treatment, which is available over the counter, is the only antihistamine to have an effect on both histamine and PAF 10.
DISCLAIMER: This editorial has been commissioned and brought to you by iNova Pharmaceuticals. Content in this editorial is for general information only and is not intended to provide medical or other professional advice. For more information on your medical condition and treatment options, speak to your healthcare professional.
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- Healthychildren.org – Hive Symptoms (2015) at https://www.healthychildren.org/English/health-issues/conditions/skin/Pages/Hives-Symptoms.aspx
- Q&A with Dr Tamatha Urquhart – 28 March 2019 (unpaid)
- Kids Health – Help with Hives (2018) at https://kidshealth.org/en/kids/hives.html
- Del Pozzo-Magaña, B. European Medical Journal. Chronic Urticaria In Children: A Review (November 2017) at https://www.emjreviews.com/dermatology/article/chronic-urticaria-in-children-a-review/
- Web MD. Hives and Your Skin (2017) at https://www.webmd.com/skin-problems-and-treatments/guide/hives-urticaria-angioedema#1
- Gimenez-Arnau A. et al. Rupatadine in the treatment of chronic idiopathic Urticaria: a double-blind, randomized, placebo-controlled multicentre study. Allergy 2007; 62: 539-546.
- Church MK. et al. The Scope of Pharmacological and Clinical Effects of Modern Antihistamines with a Special Focus on Rupatadine. WAO Journal. 2010; S1-S16
- National Centre for Biotechnology Information (NCBI) – Platelet-activating factor (PAF) in allergic diseases: inhibitory effects of anti-allergic drugs, ketotifen and three kampo medicines on PAF production. https://www.ncbi.nlm.nih.gov/pubmed/1726443 (Website accessed on 24 April 2018).
- Package insert
- Picado C. Rupatadine: pharmacological profile and its use in the treatment of allergic disorders. Expert Opinion in Pharmacotherapy 2006;7(14):1989-2001.