Hives (urticaria): causes, treatment and when it is an emergency
What hives are, common triggers, short-lived versus chronic hives, how they are treated, and the warning signs of a severe allergic reaction.
Also known as: Urticaria
What hives are
Hives, also called urticaria, are raised, itchy welts on the skin. They happen when mast cells in the skin release histamine and other chemicals, which make small blood vessels leak fluid into the surrounding skin. Each welt usually fades within a day, but new ones can keep appearing elsewhere.
Sometimes the swelling is deeper, affecting the lips, eyelids, hands, feet or genitals. This is called angioedema. It can occur with or without hives.
Doctors divide hives into acute urticaria, which lasts less than six weeks and often has a trigger such as an infection, food or medicine, and chronic urticaria, which continues for six weeks or more. In most chronic cases no external trigger is found; this is called chronic spontaneous urticaria and is thought to involve the immune system. Hives are not contagious.
Symptoms
- Raised itchy welts that are pink, red or skin-coloured, sometimes with a pale centre
- Welts that move around — fading in one place and appearing in another within hours
- Welts that join to form large patches
- Swelling of lips or eyelids, hands or feet
- Itching, burning or stinging
A rash in which each spot lasts more than a day or two, leaves bruising, or is painful rather than itchy may be a different condition, such as urticarial vasculitis, and should be checked by a doctor.
Causes and triggers
Common triggers include:
- Viral and other infections, a very common cause in children
- Foods such as nuts, eggs, shellfish, milk and some fruits
- Medicines, including antibiotics, painkillers such as aspirin and other anti-inflammatories, and some blood pressure medicines
- Insect stings
- Physical triggers: pressure, scratching, cold, heat, sunlight, exercise, sweating or water
- Latex and contact with plants or animals
- Stress and alcohol, which can worsen existing hives
Chronic spontaneous urticaria is sometimes associated with thyroid autoimmune disease. Anti-inflammatory painkillers can make chronic hives worse in many people.
How it is diagnosed
Hives are recognised by their appearance, ideally with photos of the rash. The key is a clinical assessment: when the welts started, how long each lasts, possible triggers in the hours before, new medicines or foods, infections, and any physical triggers.
For acute hives with an obvious trigger, no tests are usually needed. Allergy testing (skin prick or blood tests) is useful when a specific food, sting or medicine is suspected. For chronic hives, a limited set of blood tests — a blood count, inflammation markers and thyroid tests — is often enough. Extensive allergy panels are rarely helpful in chronic spontaneous urticaria. A skin biopsy is done only if vasculitis is suspected.
Which doctor to see
A dermatologist manages persistent or chronic hives. An internal medicine physician can investigate hives linked to other conditions. An allergist is helpful when a food, sting or medicine allergy is suspected. A general physician can treat a short episode.
You can find dermatologists in Bengaluru and internal medicine physicians on The Doctor Index, each with a registration you can check.
Treatment
Antihistamines
Non-drowsy antihistamines, such as cetirizine, levocetirizine, fexofenadine or bilastine, taken regularly are the main treatment. For chronic hives, doctors often increase the amount above the usual level under supervision if standard treatment is not enough. Take them every day as advised, not only when welts appear, until your doctor reviews you.
Short courses of steroids
A short course of steroids may be used for severe acute hives or angioedema. Long-term steroid tablets are avoided because of their side effects.
For chronic hives that do not respond
Omalizumab, an injection given at regular intervals, is effective for many people with chronic spontaneous urticaria that does not respond to antihistamines. Ciclosporin, an immune-suppressing medicine, is another option under specialist monitoring.
Emergency treatment
Adrenaline (epinephrine) injected into the thigh muscle is the emergency treatment for anaphylaxis. People who have had anaphylaxis may be prescribed an auto-injector and taught how to use it.
Living with hives
Avoid known triggers, including anti-inflammatory painkillers if they worsen your hives. Wear loose, cool clothing, keep skin cool, and use a soothing moisturiser. Keep a diary of flares and possible triggers. Chronic hives can be exhausting and affect sleep and mood, but in most people they eventually settle, often within a few years. Regular review lets your doctor step treatment up or down.
When it is an emergency
Call 112 or 108, or go to the nearest emergency department, for:
- Swelling of the tongue, throat or face, or a hoarse voice
- Difficulty breathing, wheezing or a tight chest
- Difficulty swallowing
- Dizziness, fainting, a fast heartbeat or feeling faint
- Vomiting or severe abdominal pain with hives, especially after a food, sting or medicine
Use an adrenaline auto-injector if one has been prescribed, then call for help. Lie the person flat with legs raised, unless they are struggling to breathe, in which case let them sit up.
Questions to ask at your appointment
- Is this acute or chronic urticaria?
- Could a food, medicine or infection be the trigger?
- Do I need allergy testing or blood tests?
- Which antihistamine should I take, how often, and for how long?
- Should I avoid any painkillers or other medicines?
- Do I need an adrenaline auto-injector?
Common questions
Questions people ask
- Are hives contagious?
- No. Hives are a reaction in the skin and cannot spread from person to person. If hives follow a viral infection, the infection itself may be contagious, but the hives are not. Children with hives can usually attend school if they are otherwise well.
- Why can't the doctor find what is causing my hives?
- In chronic hives lasting more than six weeks, an external trigger is usually not found. The immune system itself is often involved. Extensive allergy tests rarely help in this situation, and treatment with regular antihistamines works for many people regardless of the cause.
- Is it safe to take antihistamines every day?
- Modern non-drowsy antihistamines are generally safe for daily use over long periods when taken as advised by your doctor. Older, drowsy antihistamines cause sleepiness and are best avoided for long-term use, especially in children and older adults.
- Do I need to stop eating certain foods?
- Only if a specific food has clearly triggered hives or other allergic symptoms. Most chronic hives are not caused by food, and restrictive diets rarely help. Your doctor can advise whether allergy testing is useful before you cut out foods.
This condition is usually assessed by a dermatologist. Every profile shows the doctor’s registration and what has been checked.
Dermatologists in Bangalore
A few dermatologists listed on The Doctor Index. They are shown because of their speciality, not a stated interest in Hives; ask the clinic whether the doctor sees it.
Related conditions
All allergy and immunology conditions →
Practical reading
All postsSources
- MedlinePlus, US National Library of Medicine — Hives
- American Academy of Dermatology — Hives: overview
- MedlinePlus, National Library of Medicine — Hives — Public-domain health-topic summary
Hives (urticaria): causes, treatment and when it is an emergency is original text by The Doctor Index; the compiled source draft was used for research. Source: MedlinePlus, National Library of Medicine. Orphadata Science: Free access data from Orphanet. © INSERM 1999; July 2026 data, CC BY 4.0. This product uses the Human Phenotype Ontology (hp/releases/2026-09-01). Only sources listed for this article apply. Source material has been selected and arranged; HPO definitions are reproduced without alteration. No source organisation endorses this compilation. Köhler S et al. The Human Phenotype Ontology project: linking molecular biology and disease through phenotype data. Nucleic Acids Research 2014;42(D1):D966–D974. doi:10.1093/nar/gkt1026.
General information, not advice about your situation. Errors can be reported through the corrections process. Reference TDI-C-1172.