White heads are closed comedones, which are swollen secretory bags of sweat glands. They contain sebum and dead skin cells. When bacteria grow in these, they form acne. Whiteheads are basically a pre-acne condition and extremely prone to develop into acne depending on skin type and the duration for which they are left unheeded.
(Dr Deepali Bhardwaj is a renowned skincare expert and holds an MD in dermatology from
the University of Seychelles. She runs The Skin and Hair Clinic at Uday Park in South Delhi.