A 4-year-old boy from rural Maharashtra presents with his mother complaining of itchy sores on his legs for 3 days. On examination, you find multiple honey-crusted lesions with erythematous bases on the anterior shins and knees. The child has a history of recent chickenpox. There is no fever, and regional lymph nodes are not enlarged. A Gram stain of the exudate shows Gram-positive cocci in clusters. What is the most likely diagnosis?