The excerpt featuring Dr. Girish, a consultant dermatologist, explains that acne can be broadly categorized into inflammatory and non-inflammatory types, distinguishing the two by the presence or absence of inflammation and swelling. Non-inflammatory acne lacks redness or pain, typically manifesting as open or closed comedones near the skin’s surface and often treated with topical retinoids. Conversely, inflammatory acne is characterized by redness, swelling, and pain, includes conditions like papules and cysts, and lies deeper within the skin. The appropriate treatment for acne is also addressed, noting that severe inflammatory cases may require oral antibiotics or isotretinoin, whereas milder forms can be managed with topical treatments.