Acne

What are the clinical features of acne vulgaris?

Acne most often affects the face, but it may spread to involve the neck, chest and back, and sometimes even more extensively over the body.

Individual lesions are centred on the pilosebaceous unit, ie the hair follicle and its associated oil gland. Several types of acne spots occur, often at the same time. They may be inflammatory papules, pustules and nodules; or non-inflamed comedones and pseudocysts.

Superficial lesions

• Open and closed comedones (blackheads and whiteheads)
• Papules (small, tender red bumps)
• Pustules (white or yellow "squeezable" spots)

Deeper lesions

• Nodules (large painful red lumps)
• Pseudocysts (cyst-like fluctuant swellings)

Secondary lesions

• Excoriations (picked or scratched spots)
• Erythematous macules (red marks from recently healed spots, best seen in in fair skin)
• Pigmented macules (dark marks from old spots, mostly affecting those with dark skin)
• Scars of various types

Individual acne lesions usually last less than 2 weeks but the deeper papules and nodules may persist for months. Many acne patients also have oily skin (seborrhoea).