Hives (Urticaria): Pictures, Causes & Treatment
Hives, known medically as urticaria, are raised itchy welts (weals) that appear suddenly when histamine is released into the skin. Individual welts move around and typically fade within 24 hours, leaving no mark behind.
Medically reviewed by Dr. Celina Kazumi Iwasa, MD · Last reviewed 2026-08-23
Quick answer
Hives are raised, itchy welts that appear suddenly, change shape and location, and usually disappear within 24 hours without bruising or scarring. They are caused by histamine release triggered by infection, medication, food, heat, pressure, exercise or, in chronic cases, an autoimmune process. Most cases settle with non-drowsy antihistamines. Seek emergency care if hives come with lip or tongue swelling, throat tightness, wheeze or faintness.
What hives looks like
A hive is a smooth, raised weal with a pale centre and a surrounding flare. Welts range from a few millimetres to palm-sized patches and often join into large maps. The key diagnostic feature is that any single welt lasts less than 24 hours — the rash as a whole may continue for days or weeks as new welts replace old ones.
Common locations
- Anywhere on the body, often the trunk, arms and legs
- Areas of pressure — waistband, bra line, under straps
- Face, lips and eyelids as deeper swelling (angioedema)
- Palms and soles, which can feel burning rather than itchy
Typical signs
- Raised welts that blanch when pressed
- Intense itch, sometimes stinging or burning
- Individual welts fading within 24 hours
- Welts appearing in new places as old ones clear
- Deeper puffy swelling of lips, eyelids or hands (angioedema)
On brown and Black skin
On brown and Black skin, hives may show little or no redness; look for raised, shiny, slightly lighter or darker swellings that are easier to feel than to see.
Causes and triggers
Acute hives (under six weeks) usually have an identifiable trigger. Chronic hives (over six weeks) are often spontaneous and autoimmune, with no external trigger found in the majority of cases — which does not make them less real or less treatable.
| Trigger | Why it matters |
|---|---|
| Viral infection | The single most common cause of acute hives, particularly in children. |
| Medications | Antibiotics, NSAIDs, opioids and ACE inhibitors are frequent culprits. |
| Foods | Nuts, shellfish, eggs, milk and wheat — usually within minutes to two hours of eating. |
| Physical triggers | Pressure, cold, heat, sunlight, water, vibration and exercise can each induce welts (inducible urticaria). |
| Insect stings | Local or generalised urticaria after a sting can precede a more serious allergic reaction. |
| Autoimmune activity | In chronic spontaneous urticaria, autoantibodies activate mast cells without an outside trigger; thyroid autoimmunity is often associated. |
Conditions that look similar
If welts last longer than a day, hurt more than they itch, or leave marks, the diagnosis is probably not ordinary urticaria.
| Condition | How to tell it apart |
|---|---|
| Urticarial vasculitis | Welts persist beyond 24 hours, burn rather than itch and leave bruising or brown staining. Needs medical review. |
| Insect bite reactions | Grouped, firm bumps often with a central punctum that persist for days in the same spot. |
| Eczema | Dry, scaly, fixed patches rather than smooth migrating welts. |
| Erythema multiforme | Fixed target-shaped lesions with a dusky centre, often on the hands and feet. |
| Drug rash | Widespread flat red spots that spread and persist, usually days after starting a new medicine. |
Treatment options
The aim is to suppress symptoms completely while the underlying cause resolves or the condition burns out. Most hives are managed with antihistamines alone.
Non-sedating antihistamines
Second-generation antihistamines such as cetirizine, loratadine or fexofenadine are first line. For persistent hives, clinicians often increase the dose above the standard packet dose — do this only on medical advice.
Trigger avoidance
Stop any suspected new medicine after checking with your prescriber, and avoid known food, pressure, heat or cold triggers. Alcohol, NSAIDs, heat and stress worsen most hives regardless of cause.
Short steroid course
A brief course of oral corticosteroids may be used for a severe acute flare. Steroids are not appropriate for long-term control of chronic hives.
Specialist treatment for chronic hives
If hives persist beyond six weeks despite antihistamines, dermatology or immunology may add omalizumab or ciclosporin, which are highly effective for chronic spontaneous urticaria.
Symptom relief
Cool showers, cold compresses, loose cotton clothing and a cool bedroom reduce itch. Scratching releases more histamine and prolongs the flare.
When to see a doctor
Most hives are not dangerous, but the combination of hives with breathing or circulatory symptoms is an emergency. Book a routine appointment if welts persist beyond six weeks or keep returning.
Red flags
- Swelling of the lips, tongue or throat, or a tight throat — call emergency services
- Wheezing, difficulty breathing, faintness or collapse — call emergency services
- Hives with fever, joint pain or feeling generally unwell
- Individual welts lasting more than 24 hours or leaving bruises
- Hives starting after a new medication, sting or injection
Frequently asked questions
How long do hives last?
Any single hive should fade within 24 hours. An acute episode — new welts replacing old ones — usually settles within days to a few weeks. Hives that continue for more than six weeks are classed as chronic urticaria and deserve a medical review.
How do I get rid of hives fast?
Take a non-sedating antihistamine such as cetirizine, loratadine or fexofenadine, apply cool compresses, wear loose cotton clothing and keep cool. Avoid alcohol, NSAIDs, hot showers and scratching, all of which release more histamine. Seek urgent care if you develop lip, tongue or throat swelling or any breathing difficulty.
What causes hives with no obvious trigger?
In chronic spontaneous urticaria, mast cells are activated by the body's own autoantibodies rather than by an external allergen, so extensive allergy testing often finds nothing. This is common, is not dangerous in itself, and responds well to regular high-dose antihistamines or omalizumab.
Are hives an allergic reaction?
Sometimes. Hives can be the skin sign of an allergy to food, medication or an insect sting, but most cases — especially in children — follow a viral infection instead. Hives alone are not anaphylaxis; anaphylaxis involves breathing difficulty, throat swelling or a drop in blood pressure and needs emergency treatment.
Can stress cause hives?
Stress rarely causes hives on its own, but it lowers the threshold at which mast cells release histamine, so it can trigger a flare or make existing urticaria markedly worse. Sleep, exercise and stress management are legitimate parts of chronic hives care.
Are hives contagious?
No. Hives cannot be spread from person to person, even when they are triggered by a viral infection. The virus may be contagious; the rash is not.
Not sure if it is hives?
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Check your skin nowRelated guides
- Hives (urticaria): full clinical A–Z entry
- Skin rash types: identify a rash by pattern
- Heat rash: how it differs from hives
- Contact dermatitis
- Skin symptom pictures library
This page is for general information and does not replace a medical consultation. If you are worried about a skin change, see a qualified clinician.