Introduction

Acne, or acne vulgaris, is a chronic inflammatory skin condition affecting mainly the face, back and chest. It is characterised by the blockage and inflammation of the pilosebaceous unit (the hair follicle, hair shaft and sebaceous gland). Acne is identified by the presence of comedones (non-inflammatory lesions), which may be open (blackheads) or closed (whiteheads), as well as papules (inflammatory lesions) and pustules (pus-filled spots). Acne can range from a few spots to a more severe problem that may cause long-term scarring and affect the person’s mental health. Up to 95 per cent of adolescents in Western industrialised countries are affected by acne to some extent.^{1, 2}