Urticaria
Urticaria, commonly called hives, is a skin reaction that produces raised, pale-red welts with a distinct itch. Individual weals typically fade within 24 hours, but new ones can keep appearing for days or even weeks. When the same episodes repeat for six weeks or more, the condition is classified as chronic urticaria.
Key points
- Individual hives usually move or fade within a day; fixed painful or bruising lesions suggest another diagnosis.
- Acute hives may follow infection, food, medicine or a sting, while chronic urticaria often has no external allergic trigger.
- Antihistamines treat itch and weals but do not replace adrenaline and emergency care for anaphylaxis.
An antihistamine listing cannot determine the trigger or severity; breathing, circulation, lesion pattern, sedation and other medicines guide care.
What patterns help identify the cause?
Timing after a new medicine, food or sting can suggest an acute trigger. Heat, cold, pressure and exercise can induce physical urticaria. Broad allergy testing is usually unhelpful in chronic spontaneous disease without a consistent exposure pattern.
How are symptoms controlled?
Fexofenadine and bilastine are less sedating options. Hydroxyzine can impair alertness and combines poorly with alcohol or other sedatives. Persistent disease may need specialist escalation; see allergy relief for context.
When to seek urgent care
Call emergency services for tongue or throat swelling, breathing difficulty, wheeze, faintness, collapse or rapidly progressing symptoms after a likely allergen. Use prescribed adrenaline immediately when an anaphylaxis plan says to do so.
Further reading
Related articles
Compare older sedating and newer less-sedating antihistamines, including driving, alcohol, duplicate products and why individual drowsiness varies.
Read guide