Understanding Urticaria

TSMH | Pediatric Series |Understanding Urticaria | Understanding Pediatric Urinary Tract Infections | date：2023-01/01

What is Urticaria?

Urticaria is a condition characterized by the dilation of small blood vessels beneath the skin, often triggered by various factors including allergic reactions. It manifests as itchy, red raised rashes on the skin, resembling mosquito bites. In typical cases of acute urticaria, the rashes usually disappear within approximately 24 hours, but they can frequently recur, with the rash appearing and disappearing repeatedly. The rashes often have a map-like border, are abnormally itchy, and are commonly distributed on the limbs and trunk, although they can occur anywhere on the body. The size and shape of the rashes can vary.
Urticaria that occurs within a period of 6 weeks is referred to as acute urticaria, while urticaria lasting for more than 6 weeks is classified as chronic urticaria.

What are the causes of urticaria?

• Idiopathic (Unknown cause)
• Immune-related reactions: The body's immune system reacts to food, medications, or infections, or it can be triggered by immune antibodies or complement factors.
  • Food: Eggs, peanuts and nuts, shellfish, fish, wheat, milk, soy milk, and certain fruits.
  • Infections: Hepatitis, parasitic infections, Epstein-Barr virus, Streptococcus pyogenes, Candida, etc.
• Less immune-related:
  • Food: Strawberries, cheese, spinach, eggplant, tomatoes, certain food colorings, and additives.
  • Medications: Penicillin antibiotics, aspirin, opioids, contrast agents, etc.
  • Physical factors: Cold, heat, pressure, sunlight, and other physical stimuli that rarely persist for more than 1 hour.

How can parents identify possible causes?

Parents should pay attention to whether their child has taken any medications, consumed allergenic foods and additives, or experienced fever, infections, or other discomforts before the occurrence of urticaria. They should also observe if urticaria tends to happen after exposure to cold, heat, or physical activities causing sweating.

Treatment and Care Education

• Identify and avoid triggering factors for allergies in children.
  • Avoid easily allergenic foods and medications such as eggs, peanuts and nuts, shellfish, fish, wheat, milk, etc. Pay attention to the correlation between these items and the occurrence of urticaria.
  • Consume fresh foods as much as possible and avoid preservatives, additives, artificial colors, and spicy foods.
  • Introduce complementary foods one at a time, gradually increasing amount only after observing no allergic reactions. Children with allergic tendencies should not be introduced to complementary foods too early, and certain items like egg yolks and wheat flour should be avoided initially.
  • Avoid consuming extremely hot, cold, or icy foods and drink plenty of water to promote metabolism.
  • When treating fever, use acetaminophen (unless allergic to it) as the main medication.
  • For stress-induced urticaria, wear loose, lightweight, and breathable clothing.
  • For sunlight-induced urticaria, avoid direct sun exposure and use protective clothing and sunscreen lotions.
• Daily Living Care
  • Avoid excessively hot or cold environments and excessive sweating. Avoid taking showers with very hot water
  • Wear loose, lightweight, breathable, and sweat-absorbing cotton clothing.
  • Prevent mosquito bites by using mosquito repellents when going outdoors and avoid contact with allergens.
  • Apply a cooling anti-itch lotion such as ice packs, prickly heat balm, or peppermint oil to reduce itching sensation.
• Follow the doctor's instructions and take antihistamines or short-term steroids to alleviate itching and reduce recurrent episodes.