Four clients are receiving tyrosine kinase inhibitors (TKIs). Which of these four clients would the nurse assess first?

Dry, itchy, peeling skin

Serum potassium of 2.8 mEq/L (2.8 mmol/L)

Weight gain of 0.5 lb (1.1 kg) in 1 day

Serum calcium of 9.2 mg/dL (2.3 mmol/L)