Allergic Urticaria ICD-10: L50.0

Causes, Symptoms, and When to Take Action Allergic urticaria is a skin reaction characterized by the sudden appearance of itchy, raised welts caused by an allergic response — most often to medications. It is a form of hives triggered by the immune system's reaction to a specific substance. How It Looks Texture: Raised, swollen welts that may feel warm or firm Color: Red or skin-colored Shape: Round, oval, or irregular patches; welts may merge into larger areas Location: Can appear anywhere on the body, often shifting location as old welts fade and new ones appear Why Does It Appear? Triggered by an allergic reaction to certain medications The immune system releases histamine and other chemicals into the skin, leading to inflammation, swelling, and itching The reaction can occur minutes to hours after exposure to the medication Should You Be Concerned? Most episodes of allergic urticaria are temporary, but medical attention is necessary if: The welts are widespread or last more than a few days Swelling involves the lips, tongue, or throat There is difficulty breathing, dizziness, or other systemic symptoms Can You Prevent It? Avoid the medication or trigger once identified Inform healthcare providers about previous allergic reactions before taking new medications Monitor for early signs of skin changes when starting a new treatment 👉 How Piel AI Can Help Piel AI allows you to track how welts appear and resolve over time through regular photos. While not diagnostic, it helps identify recurring reactions or patterns to share with your healthcare provider. Summary Allergic urticaria is a type of hives caused by an allergic reaction to medications. It appears as red or skin-colored welts that may come and go quickly. Though often short-lived, severe reactions require prompt medical evaluation. Avoiding known triggers and close monitoring help prevent recurrence.