(ak′nē)

[Ult. fr. acme]
An inflammatory disease of the sebaceous follicles of the skin, marked by comedones, papules, and pustules. It is exceptionally common in puberty and adolescence. Acne usually affects the face, chest, back, and shoulders. In severe cases, cysts, nodules, and scarring occur.
SYN: SEE: common acne; SEE: acne vulgaris

ETIOLOGY
The cause is unknown, but predisposing factors include hereditary tendencies and disturbances in the androgen-estrogen balance. Acne begins at puberty when the increased secretion of androgen in both males and females increases the size and activity of the pilosebaceous glands. Specific inciting factors may include food allergies, endocrine disorders, therapy with adrenal corticosteroid hormones, and psychogenic factors. Vitamin deficiencies, ingestion of halogens, and contact with chemicals such as tar and chlorinated hydrocarbons may be specific causative factors. The fact that bacteria are important once the disease is present is indicated by the successful results following antibiotic therapy. The lesions may become worse in women and girls before the menstrual period.

SYMPTOMS
Acne vulgaris is marked by either papules, comedones with black centers (pustules), or hypertrophied nodules caused by overgrowth of connective tissue. In the indurative type, the lesions are deep-seated and cause scarring. The face, neck, and shoulders are common sites. Acne may be obstinate and recurrent.

TREATMENT
Treatments include skin cleansing, topical agents, e.g., azelaic acid or benzoyl peroxide or vitamin A derivatives, and oral or topical antibacterial drugs.

PATIENT CARE
The patient is instructed to wash the skin thoroughly but gently, avoiding intense scrubbing and skin abrasion; to keep hands away from the face and other sites of lesions; to limit the use of cosmetics; and to observe for, recognize, and avoid or modify predisposing factors that may cause exacerbations. The need to reduce sun exposure is explained, and the patient is advised to use a sunscreen agent when vitamin A acid or tetracycline is prescribed. Information is provided to fill knowledge gaps or correct misconceptions, and emotional support and understanding are offered, particularly if the patient is an adolescent. Patients (and others) need to be aware that extensive use of antibiotic treatment for acne increases the prevalence of antibiotic-resistant facial bacteria and can affect treatment response. Most improvement occurs during the first 6 weeks of therapy, whatever the regimen. More than half of all patients respond to therapy. Colonization with tetracycline-resistant propionibacteria diminishes response to all oral antibiotic regimens. Skin irritation as an adverse effect to treatment occurs most commonly with topical benzoyl peroxide alone, which is the most cost-effective treatment. Adding topical erythromycin may help reduce irritation and increase efficacy.

Because of the teratogenicity of some acne medications (such as isotretinoin), pregnancy must be avoided during their use.

acne atrophica

Acne with residual pitting and scarring.

bromide acne

The characteristic acne caused by bromide.

acne ciliaris

Acne that affects the edges of the eyelids.

common acne

SEE: Acne.

acne conglobata

Acne vulgaris with abscesses, cysts, and sinuses that leave scars.

cystic acne

Acne with cysts containing keratin and sebum.

acne excorie

Damage to skin affected by acne that results from picking or scratching.

acne fulminans

A rare type of acne in teenage boys, marked by inflamed, tender, ulcerative, and crusting lesions of the upper trunk and face. It has a sudden onset and is accompanied by fever, leukocytosis, and an elevated sedimentation rate. About half of the cases have inflammation of several joints.

halogen acne

Acne due to exposure to halogens such as bromine, chlorine, or iodine.

acne indurata

Acne vulgaris with chronic, discolored, indurated surfaces.

keloid acne

SEE: Acne keloidalis nuchae.

acne keloidalis nuchae

Chronic follicular infection of the skin at the occiput (base of the skull) and the neck. It occurs most often in men of African heritage and causes scars and thickening of the skin.
SYN: SEE: keloid acne

acne keratosa

Acne in which suppurating nodules crust over to form horny plugs. These occur at the corners of the mouth.

acne neonatorum

Acne occurring in newborns. It is common, appearing about the second to fourth week of life. Comedones, inflamed papules, and pustules may be seen (the latter yield staphylococcal species when cultured). The rash typically resolves spontaneously by the third or fourth month of life. Lesions are typically seen on the chin, cheeks, and forehead. Usually no treatment is required, but keratolytic agents may be used for severe cases.

acne papulosa

Acne characterized by formation of papules with very little inflammation.

petroleum acne

Acne that may occur in those who work with petroleum and oils.

acne pustulosa

Acne with pustule formation and subsequent deep scars.

acne rosacea

SEE: Rosacea.

steroid acne

Acne caused by systemic or topical use of corticosteroid drugs.

summer acne

Acne that appears only in hot, humid weather or that is much worse in such weather. Although the exact cause is unknown, the condition is not caused by increased exposure to the sun's rays.

tropical acne

Severe acne caused by or aggravated by living in a hot, humid climate. The skin of the thorax, back, and legs is most commonly affected.

acne urticaria

An acneiform eruption of itching wheals.

acne varioliformis

Vesiculopustular folliculitis that occurs mostly on the temples and frontal margins of the scalp but may be seen on the chest, back, or nose.

acne vulgaris

SEE: Acne.