RASH is a standardised mnemonic used to confirm the symptoms associated with an anaphylaxis medical emergency. Anaphylaxis is a severe, potentially life-threatening systemic hypersensitivity reaction with a rapid onset. Anaphylaxis can exist with any combination of the signs and symptoms below, but may also be limited to a single body system e.g. isolated hypotension or isolated respiratory distress in the presence of a known antigen.
| R | Respiratory – Respiratory distress, shortness of breath, wheeze, cough or stridor |
| A | Abdominal – Pain, cramping, nausea, vomiting or diarrhoea |
| S | Skin – Hives, welts, itching, flushing or angioedema |
| H | Hypotension |