Rash with stomach flu: what to know

Gastroenteritis commonly causes diarrhoea, nausea, vomiting, stomach cramps, loss of appetite, and sometimes fever. A body rash may occur with a particular infection, a separate viral illness, a food reaction, or a medicine reaction. It should not be assumed to come from the stomach infection without considering its timing and appearance.

Think about whether the rash started before or after vomiting, diarrhoea, fever, a new food, or a medicine. Dry mouth, dark urine, dizziness, unusual sleepiness, or passing very little urine can point to dehydration.

Take frequent small sips of water or an oral rehydration drink. When appetite returns, choose simple foods and resume usual eating gradually. Wash hands with soap and water, clean shared surfaces, and avoid preparing food for others while diarrhoea or vomiting continues.

Keep the rash cool and avoid scratching or fragranced products. Photograph changes, track urine and fluid intake, and do not use anti-diarrhoea medicines or antibiotics without advice, particularly for children or people with chronic conditions.

Seek urgent help for trouble breathing, facial swelling, faintness, confusion, a purple rash that does not fade when pressed, severe abdominal pain, blood in vomit or stool, or inability to keep fluids down. Arrange prompt assessment for signs of dehydration, persistent fever, worsening rash, or a child who is unusually quiet or difficult to wake.

Ask whether the rash fits the stomach infection or needs separate testing, how to replace fluids, when isolation can end, and which medicines are suitable. Mention travel, shared meals, sick contacts, and any recent antibiotic use.