White heads are caused by accumulation of secreted oil and sebum from thr skin. this oil accumulates in the pores and hardens to form white head. it is usually found on Forehead, Cheeks, near nose, near lips, on neck and chest.
You need to keep your skin clean with proper cleansers and face washes to reduce white heads formation. Apply good moisturizer and facial creams to keep your skin hydrated all the time.