What grade of acne is characterized by red and inflamed skin with many comedones?

The description of acne characterized by red and inflamed skin along with numerous comedones aligns with Grade II acne. This grade features moderate inflammatory lesions, including papules and pustules, and is also marked by the presence of both open and closed comedones.

Grade I, on the other hand, generally includes mild acne with only non-inflammatory lesions, such as a few comedones but little to no redness or inflammation. Grade III is more severe, typically involving more inflamed lesions and can include nodular forms of acne. Grade IV represents the most serious type of acne, often with extensive inflammatory nodules or cysts, which is far beyond the symptoms outlined in the question.

Thus, Grade II is the most fitting classification for acne that presents significant redness, inflammation, and multiple comedones.