Acute Caremiddle twist
A 24-year-old man is brought to the surf club first aid room at a Perth beach in February. Ten minutes ago, while swimming, he felt sudden severe burning pain in his right forearm. There is a string of raised red weals in a wavy line along the flexor surface, with two translucent threads stuck to the skin. Pulse is 96/min, blood pressure 128/74 mmHg, and there is no rash elsewhere and no abdominal or back pain. Which one of the following measures will most effectively relieve his pain?