Acne vulgaris

The common type of acne is called acne vulgaris. It is a condition that mainly affects adolescents but may persist or even become more severe in adulthood. Most, but not all, acne patients have oily skin (seborrhoea).

Clinical features

Acne vulgaris may occur on the face, chest, back and sometimes even more extensively. Several types of acne spots occur, often at the same time.

Non-inflammatory lesions:

• Open comedones (blackheads)
• Closed comedones (whiteheads)
• Uninflamed nodules (sometimes called cysts)

Inflammatory lesions:

• Papules (small red bumps)
• Pustules (white or yellow ‘squeezable’ spots)
• Inflamed nodules (large red lumps)

Secondary lesions:

• Excoriations (picked or scratched spots)
• Erythematous macules (red marks from recently healed spots, mostly in fair skin)
• Pigmented macules (dark marks from old spots, mostly in dark skin)
• Scars

Individual acne lesions usually last less than two weeks but the deeper papules and nodules may persist for months.

Acne vulgaris

More images of acne ...

• Facial acne
• Back acne

Acne grading

Acne may be classified as mild, moderate or severe¹. Comedones and inflammatory lesions are usually considered separately.

Mild acne:

• <20 comedones
• <15 inflammatory lesions
• Or, total lesion count <30

Moderate acne:

• 20-100 comedones
• 15-50 inflammatory lesions
• or, total lesion count 30-125

Severe acne:

• >5 cysts
• Total comedo count >100
• Total inflammatory count >50
• Or total lesion count >125

Classification of acne

Mild acne

Moderate acne

Severe acne

Many dermatologists assess the severity of a patient's acne more precisely by using a grading scale, such as the one developed by the Leeds' group. The inflammatory lesions are compared with a set of standard photographs to determine the grade, which may be 1 (very mild) to 12 (exceptionally severe).

In clinical trials evaluating acne treatment, the numbers of uninflamed and inflamed lesions are carefully counted at regular intervals. It is remarkably difficult to count consistently.

Treatment

Which treatment is best depends on the patient's age and sex, the extent and the severity of the acne.

• Treatment for mild acne
• Treatment for moderate acne
• Treatment for severe acne