Hello,
Blackhead is a blackish bump or plug on the skin and is a type of acne vulgaris. It is caused by excess oils that have accumulated in the sebaceous
acid or benzoyl peroxide. This helps is soaking the oil and helps in peeling away the blackheads. If benzoyl peroxide leaves your skin dry, apply an oil-free moisturizer after 10 mins of applying benzoyl peroxide.
If the symptoms still persist then please consult a dermatologist and get cysts ruled out.
I hope it helps. Take care and regards.