After exposure to a powerful pesticide, what is the first action to take when treating a patient with breathing difficulty and skin irritation?

When treating a patient who has been exposed to a powerful pesticide and is experiencing breathing difficulties and skin irritation, the first action should be to flush the pesticide off the skin with copious amounts of water. This is crucial to help remove the harmful chemical from the skin, which can alleviate irritation and prevent further absorption into the body.

Immediate decontamination is vital in toxic exposures, especially with substances like pesticides that can cause a range of adverse effects, including respiratory distress. By thoroughly washing the exposed area, you not only reduce the risk of systemic absorption but also minimize the chance of continued exposure, which could worsen the patient's condition.

In this scenario, applying supplemental oxygen, obtaining vital signs and medical history, or brushing off the pesticide would not adequately address the immediate need for decontamination and could allow the toxin to continue affecting the patient's health. Therefore, flushing with water is the most appropriate and effective first step in managing such a toxic exposure.