A 4-year-old child presented with a continuous high-grade fever and red painful skin nodules. The nodules initially appeared over his shins and later progressed to involve the thighs, trunk, upper extremities, and face. Subsequently, the nodules spread over his scalp and there was an evident progressive loss of scalp hair.

On examination, his temperature was noted up to 103°F.

What other examinations and investigations should be conducted for this patient?