Medical term

Explanation

Acne conglobata

A severe form of acne presenting with numerous comedones and large abscesses^a

Acne fulminans

A severe form of cystic acne presenting with highly inflammatory nodules and plaques^a

Acne mechanica

A form of acne caused by the pressure of tight clothing or friction^b

Acne vulgaris

A common chronic skin disorder of sebaceous follicles, mainly affecting the face, chest, and back^a

Chemokine

A group of small cytokines that act as chemical messengers to induce chemotaxis in leukocytes^c

Comedone

A clogged hair follicle in the skin. It can present as a blackhead or whitehead^a

Cytokine

A small protein released by cells that function as molecular messengers between cells^c

Erythema

Redness of the skin, caused by vascular congestion or increased perfusion^b

Excoriated acne

Compulsive squeezing and scratching of acne lesions with resultant scabs and scars^a

Halogen acne

A form of acne caused by iodides, bromides, and halogens^b

Hyperkeratosis

Thickening of the outer layer of skin often associated with a quantitative abnormality of keratin^b

Keratinocytes

The predominant cell type in the epidermis, forming a touch protective layer^a

Microcomedones

Early and small plugging of the follicle with excess keratin and sebum^b

Nodule

A solid mass in the skin, more than 0.5 cm in diameter^b

Papule

A circumscribed palpable elevation, less than 0.5 cm in diameter^b

Pilosebaceous unit

A structure consisting of a hair follicle, sebaceous gland, and an arrector pili muscle^b

Propionibacterium acnes

Gram‐positive bacterium related to acne development^b

Pustule

A visible accumulation of free pus^b

Scar

Skin areas of fibrous tissue replacing normal skin after injury^b

Sebum

The oily, waxy substance produced by sebaceous glands^b

Stratum corneum

The outermost layer of the epidermis, where cells have lost nuclei and cytoplasmic organelles^b

Toll‐like receptor

A class of proteins that recognise conserved products unique to microbial metabolism in immune response^c

Acne vulgaris

Acne variants:

Neonatal acne

Infantile acne

Acne conglobata

Acne fulminans

SAPHO syndrome

PAPA syndrome

Acne excoriee des jeunes filles

Acne mechanica

Acne with solid facial oedema

Acne with associated endocrinology abnormalities

Acneiform eruptions:

Steroid folliculitis

Drug‐induced acne

Epidermal growth factor receptor inhibitor associated eruption

Occupational acne and chloracne

Gram‐negative folliculitis

Radiation acne

Tropical acne

Acne aestivalis

Pseudoacne of the nasal crease

Apert syndrome