Hives in Babies

When to get help

NHS guidance asks you to call 999 immediately if the lips, mouth, throat or tongue suddenly become swollen; if breathing is very fast or there is a struggle to breathe, which may include becoming very wheezy or seeming to choke or gasp for air; if the throat feels tight or swallowing becomes difficult; if the skin, tongue or lips turn 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; if there is sudden confusion, drowsiness or dizziness; if someone faints and cannot be woken; or if a child is limp, floppy or not responding as they normally do. It notes that the child's head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face.

The same guidance adds that the person who is unwell may also have a rash that is swollen, raised or itchy, and that these can be signs of a serious allergic reaction needing immediate hospital treatment. In a baby, the swelling and the breathing are what matter; the rash is the least important part.

Ask for an urgent GP appointment or contact NHS 111 if symptoms of hives do not improve after two days, if you are worried about your child's hives, if the rash is spreading, if the hives keeps coming back, which may mean an allergy, if there is also a high temperature and your child seems unwell, or if there is swelling under the skin, which may be angioedema.

If a fever comes with it

NICE guideline NG143 on fever in under 5s states that children younger than 3 months with a temperature of 38C or higher are in a high-risk group for serious illness, and that children aged 3 to 6 months with a temperature of 39C or higher are in at least an intermediate-risk group. A baby under three months with a rash and a temperature of 38C or more should be assessed urgently.

NG143 also lists a non-blanching rash among the red, high-risk features. Hives blanches, meaning it fades when pressed. A rash that does not fade when a glass is rolled over it is a different and more urgent problem.

What hives looks like

NHS guidance describes the main symptom as an itchy rash which can be raised bumps or patches in many shapes and sizes, can appear anywhere on the body, can be in one area or spread across the body, and can feel itchy, sting or burn.

On skin tone, it is specific: the rash looks pink or red when affecting someone with white skin, and the colour of the rash can be harder to see on brown and black skin. On darker skin the raised texture is the reliable sign rather than the colour, so feeling the skin matters as much as looking at it.

The behaviour of hives is as distinctive as its appearance. Individual weals typically come and go within hours, moving around the body, so a patch on the arm at breakfast may be gone by lunch while a new patch appears on the leg. A rash that stays fixed in one place for days is probably not hives.

What triggers it

NHS guidance explains that hives occurs when something causes high levels of histamine and other chemicals to be released in the skin. The triggers it lists are eating certain foods; contact with certain plants, animals, chemicals and latex; cold, such as cold water or wind; hot, sweaty skin from exercise, emotional stress or eating spicy food; a reaction to a medicine, insect bite or sting; scratching or pressing on the skin, such as wearing itchy or tight clothing; an infection; a problem with the immune system; and rarely water or sunlight.

In babies specifically, viral infection is the most common cause by a wide margin. A baby who develops hives during or just after a cold or a tummy bug, with no new food or medicine involved, usually has virus-related hives that will resolve as the infection does. The American Academy of Pediatrics makes the same point, noting that hives in children is frequently triggered by viral illness and often has no identifiable cause at all.

Working out whether it is an allergy

Timing is what distinguishes an allergic trigger from a viral one. Food-allergic hives typically appears within minutes to about two hours of eating the food, usually involves the face first, and often comes with other signs such as vomiting, sudden distress or swelling. Viral hives appears without that time relationship, comes and goes over several days, and is not reproducible.

NHS guidance advises trying to find out what triggers hives so you can avoid those triggers where possible, which may help prevent an episode. Keeping a simple record of what your baby ate, touched and was given in the two hours before the rash appeared is more useful than testing at random.

If hives has ever come with any breathing difficulty, swelling of the face or lips, or floppiness, tell the GP explicitly, because that combination changes the assessment from a skin problem to an allergy assessment and usually leads to referral.

Treatment and what to expect

NHS guidance says a hives rash usually gets better within a few days and can often be treated at home. A pharmacist can advise on antihistamine treatment, and the guidance notes that this treatment might not be suitable for young children, so ask rather than assume. A GP might prescribe menthol cream, antihistamines or steroid tablets, and if hives does not go away with treatment a referral to a dermatologist may follow.

This page gives no medicine amounts. Follow the instructions on the packaging or ask a pharmacist about what is suitable for your baby's age.

Practical comfort measures are worth doing while you wait: keep your baby cool, because heat worsens the itch; dress them in loose cotton; keep fingernails short to limit scratching; and avoid hot baths, which typically make it flare.