Hives during fever: what to know

Hives are itchy, raised areas that can change shape and location. Fever may occur because the immune system is responding to an infection, while the rash can be part of that illness or a separate response to food, medicine, heat or another trigger. The combination does not identify one diagnosis by itself. Note the temperature, when the rash appeared, whether spots fade when pressed, and symptoms such as cough, sore throat, vomiting or reduced drinking. Children can become unwell quickly when fever affects hydration or breathing.

Offer frequent fluids and let the person rest in light clothing. Keep the room comfortably cool and avoid hot baths or fragranced products that may worsen itching. Use fever medicine only as directed for the person’s age and medical circumstances; do not combine products unless a pharmacist or clinician confirms the plan. Do not give aspirin to children. Take a photograph of a changing rash and arrange medical advice if fever persists, the person is drinking poorly, or the illness is worsening.

Get emergency help for difficulty breathing, swelling of the tongue or throat, faintness, unusual sleepiness, a seizure, or inability to wake normally. Seek urgent assessment for a purple or bruise-like rash that does not fade with pressure, severe headache with a stiff neck, repeated vomiting, signs of dehydration, or a child who is difficult to comfort. Prompt review is also needed if the rash blisters, peels, or affects the mouth or eyes.

Could the fever and hives have one cause or separate causes? How should I measure and manage the fever? Which medicines are suitable for this person? What changes in the rash should I record? How can I recognise dehydration or breathing trouble?