Clinical features

The clinical presentation mirrors the underlying pathology: (1) (2)

• comedones -
  • open (blackheads) comedones - follicles have a wider opening and are filled with plugs of sebum and sloughed off cells which appear black in colour
  • closed (whiteheads) comedones - from obstruction of the follicles with the same material but the opening is smaller
  • 'sand paper' comedones - large number of comedones that cause a rough texture
  • macrocomedones - whiteheads with a larger diameter (>1mm)
  • 'submarine' comedones - deep comedones with a diameter >5mm, often develop into nodular lesions
• papules (inflamed) and pustules (contains pus) - superficial inflammation; or nodules and cysts - deep inflammation. In very severe acne, nodules may track together and form large, deep sinuses (acne conglobata and sinus track acne)
• haemorrhagic acne maybe caused by bleeding inflammatory lesions which can be very painful and disfiguring (1)

Lesions are usually present on the forehead, nose and chin. In more severe cases, the whole of the face, upper chest and back may be affected; usually, with periorbital sparing.

Scarring is a sequel of severe acne, caused due to the rupture of the follicle and dermal damage from inflammation. Scarring typically occurs from deep lesions. Significant scarring is seen in about 22% of patients (3).

Generally, the patient has greasy skin.

Types of scars include:

• 'ice pick scars' on the cheeks (initially presents in purple colour and later fades becoming white) (4)
• 'tissue paper scars' across the shoulders
• keloid scars on the middle chest and shoulders

Post-inflammatory hyperpigmentation is another complication of acne, especially in dark-skinned people (4).

Psychological problems too can occur as a complication resulting from acne. Patients can suffer from anxiety and depression due to the cosmetic appearance of acne or the scarring (5).

References:

1. European Dermatology Forum. EDF guidelines and consensus statements​. 2016 [internet publication].

2. Cunliffe WJ, Holland DB, Clark SM, et al. Comedogenesis: some new aetiological, clinical, and therapeutic strategies. Dermatology. 2003;206(1):11-6.

3. Connolly D et al. Acne Scarring-Pathogenesis, Evaluation, and Treatment Options. J Clin Aesthet Dermatol. 2017 Sep;10(9):12-23.

4. National Institute for Health and Care Excellence. Acne vulgaris: management. Dec 2023 [internet publication].

5. Samuels DV, Rosenthal R, Lin R, et al. Acne vulgaris and risk of depression and anxiety: a meta-analytic review. J Am Acad Dermatol. 2020 Aug;83(2):532-41.