Detailed answer

To prevent blackheads on the knees, it is important to exfoliate the area regularly to remove dead skin cells and unclog pores. Use a gentle exfoliating scrub or a chemical exfoliant containing salicylic acid. Additionally, keep the area clean by washing with a mild cleanser and warm water, especially after sweating or activities that may lead to dirt buildup. After cleansing, moisturize the knees with a non-comedogenic moisturizer to maintain skin hydration without clogging the pores. It is also helpful to avoid wearing tight clothing that can cause friction and irritation on the knees, and to refrain from squeezing or picking at blackheads, as this can worsen the condition. If blackheads persist or worsen, consult a dermatologist for further evaluation and treatment options.