Key takeaways

  • Call emergency services for swollen lips, mouth, throat or tongue, or difficulty breathing. These can be signs of a serious allergic reaction, even if the rash looks mild. NHS
  • Get urgent advice if hives spread or have not improved after 2 days. The NHS also lists recurring hives, fever with feeling unwell, and swelling under the skin as reasons for review. NHS
  • A pharmacist can advise on antihistamines. Mention long-term conditions; treatment may also be unsuitable for young children. NHS
  • Look for raised patches, not just redness. The NHS photographs include skin-coloured welts on brown skin. Hives may itch, sting or burn. NHS
  • Heat and sweat can be triggers. The NHS lists exercise, emotional stress and spicy food, as well as cold, skin pressure and medicines. NHS
  • Most episodes settle within a few days. Hives follow histamine and other chemical release in the skin; it is not always possible to prevent them. NHS

An itchy patch can disappear from your arm and turn up on your leg later. That moving pattern is typical of hives. Antihistamines address the histamine release behind it; a surface cream alone does not do the same job. Swelling of the lips, mouth, throat or tongue, or difficulty breathing, needs emergency help.

What do hives look like?

Raised itchy bumps or patches, varying in size, appearing anywhere on the body.

The rash can be raised bumps or patches in many shapes and sizes, and can appear anywhere. Individual welts often come and go within hours, moving around the body, which distinguishes hives from most other rashes: a patch that was on your arm this morning may be on your leg this evening. Show a doctor a fixed patch that stays for days; that pattern is more likely to have another explanation.

On brown and black skin the rash may not look red. In image 3 of the NHS hives gallery, skin-coloured bumps around a light-brown knee range from about 2 mm to 1 cm; larger ones look puffy like blisters. Image 6 shows closely grouped patches on a dark-brown thigh, the same colour as the surrounding skin, with raised lines near the knee. Feeling the welts can be more useful than searching for redness. NHS

When is this an emergency?

When there is swelling of the airway or any difficulty breathing. Call emergency services immediately.

The NHS lists the signs that require an immediate 999 call in the UK, and the equivalent local emergency number elsewhere:

  • lips, mouth, throat or tongue suddenly becoming swollen
  • breathing very fast or struggling to breathe, becoming very wheezy, or feeling like you are choking or gasping for air
  • the throat feeling tight, or struggling to swallow
  • skin, tongue or lips turning blue, grey or pale, which on black or brown skin may be easier to see on the palms of the hands or soles of the feet
  • suddenly becoming very confused, drowsy or dizzy
  • someone fainting and not waking
  • a child becoming limp, floppy or not responding normally

A swollen, raised or itchy rash may accompany any of these. This is anaphylaxis, and it is treated as an emergency regardless of how the rash itself looks.

Separately, ask for an urgent appointment or call a medical helpline if hives symptoms do not improve after 2 days, if the rash is spreading, or if you are worried about a child’s hives.

What treats hives?

Antihistamines, with stronger options where those are not enough.

Antihistamines are the main treatment. A pharmacist can give advice on them, and the NHS adds two cautions worth repeating: tell the pharmacist if you have a long-term condition, because you might not be able to take antihistamines, and the treatment may not be suitable for young children.

The practical distinction on the shelf here is between the two generations:

  • Less-sedating antihistamines such as desloratadine and bilastine are usually the first choice for daytime use, because they control the itch without the drowsiness.
  • Sedating antihistamines such as hydroxyzine (sold here as Atarax) and cyproheptadine are older and cause drowsiness. That drowsiness is sometimes useful, since hives that keep someone awake are part of the problem, but it is a real limitation if you drive or operate machinery.

Hydroxyzine is worth understanding properly because it turns up in two different contexts. It is used for itch and urticaria, and it is also used for anxiety, and people sometimes encounter it in one setting and are surprised to be offered it in the other. It is the same medicine with the same sedating effect either way.

From a doctor, the NHS notes that treatment might include menthol cream, antihistamines or steroid tablets, and that if hives do not go away with treatment you may be referred to a dermatologist.

Montelukast is sometimes added in chronic cases, and ciclosporin is used in severe chronic urticaria that has not responded to other treatment. Both are prescriber decisions rather than self-treatment.

What sets hives off?

A trigger causing histamine release, and the trigger is not always identifiable.

The NHS list includes contact with latex, plants, animals and chemicals; medicines, bites and stings; infection; cold water or wind; and pressure from itchy or tight clothing. Hot, sweaty skin after exercise, emotional stress or spicy food can also trigger hives. NHS

Hives are not contagious. An infection can set off histamine release elsewhere in the body, but the welts themselves do not pass from one person to another.

The heat one deserves attention here. Some people get hives specifically from a rise in body temperature, from exercise, hot weather, hot showers or stress. The welts are typically small and intensely itchy, and appear where the body has heated up. In a climate where you cannot avoid being hot, recognising this pattern is more useful than trying to eliminate the trigger: it changes the approach to timing antihistamines and to managing exertion rather than to avoidance.

Sweat trapped under clothing in heat is a related irritant, which is why rinsing off and changing after being outside helps some people more than any cream.

The NHS is also clear that you cannot always prevent hives, and for a substantial number of people no trigger is ever identified. That is a normal outcome, not a failure of investigation.

What if they keep coming back?

Hives continuing beyond six weeks are called chronic urticaria. Regular treatment may be needed.

Much chronic urticaria is idiopathic: no external trigger is found. A prescriber may use regular antihistamines instead of taking them only when itchy, sometimes at higher doses under supervision, with additional medicines if needed. The antihistamine and amount are clinical decisions.

You do not have to reach six weeks before seeking help. The NHS puts recurring hives on its urgent-review list, alongside a spreading rash, fever with feeling unwell, and swelling underneath the skin that may be angioedema. It also advises review when symptoms have not improved after 2 days. NHS

The important shift is from hunting for a cause to controlling the symptoms reliably. People often spend months on elimination diets for a condition that is not driven by food, while under-treating the itch.

Do and don’t

Do:

  • Take an antihistamine early rather than waiting to see if it settles.
  • Tell the pharmacist about any long-term condition before buying one.
  • Check whether the antihistamine you are given is a sedating one before driving.
  • Cool the skin, and rinse off sweat after being outside.
  • Seek urgent advice if the rash spreads or does not improve in 2 days.
  • Call emergency services for any swelling of the mouth or throat, or breathing difficulty.

Don’t:

  • Don’t assume a rash is not hives because it is not red; feel for raised welts.
  • Don’t scratch, which worsens the histamine release.
  • Don’t take hot showers to soothe the itch if heat is your trigger.
  • Don’t start an elimination diet before getting the itch controlled.
  • Don’t ignore facial or throat swelling, even if it seems mild at first.

Where can I compare the ingredients and conditions?

Check the active ingredient and strength when comparing antihistamines.

The allergy relief category lists what is stocked here, and urticaria and chronic idiopathic urticaria approach it from the diagnosis. If your symptoms are more nose and eyes than skin, allergy in the UAE covers that side.

MedicForce option: our antihistamine listings show active ingredient and strength, which is how you tell a sedating option from a non-sedating one.

  • Hives, NHS symptoms including how the rash appears on different skin tones, when to get urgent help, the emergency signs, and treatment.
  • Allergic rhinitis, NHS relevant where hives accompany other allergic symptoms.