A 17-year-old female presents with a 10-day history of sudden-onset itchy red scaly spots scattered across her chest, back, abdomen, and proximal limbs, occurring 3 weeks after an untreated sore throat with fever. On examination, she has several hundred discrete, symmetric, droplet-shaped salmon-pink papules measuring 2–8 mm scattered predominantly over the trunk and proximal extremities, as shown marked **A** in the diagram. Each papule is surmounted by fine silvery micaceous scale with pinpoint bleeding on gentle scraping. Throat swab grows Group A beta-hemolytic streptococcus; ASO titre is 640 IU/mL and anti-DNase B is 480 IU/mL (both raised). Based on the clinical presentation and the distribution pattern marked **A**, what is the most likely diagnosis?