-IBIS-1.5.0-
tx
cutaneous system
acne vulgaris
diagnoses

definition and etiology

definition:
common disease of the pilosebaceous glands presenting as either:
noninflammatory: comedones (blackheads) and closed comedones (whiteheads)
inflammatory: (papules, pustules, and cysts); also termed "pimples" and "zits"

etiology:
Acne is the most common skin problem, comprising 25% of a dermatological practice. The lesions frequently appear on the face, but can often be seen on the chest, back and shoulders. The onset of the disease is multifactorial, a combination of factors such as hormones, sebum, bacteria and keratinization. Acne generally begins at puberty because of androgen production causing a change in the size and activity of the pilosebaceous glands.

Propionibacterium acnes are the main bacteria (along with Staph aureus) initiating the thickening of the hair follicle by cleaving free fatty acids that irritate the follicle's lining. The thickening leads to the impaction of sebum and keratin, and eventually causes follicle rupture, producing an inflammatory reaction responsible for the formation of papules, pustules and cysts.

Other important etiologic factors include:
• oil-based cosmetics
• improper diet and food sensitivities
• assorted compounds (e.g. corticosteroids, halogens)
• industrial pollutants (e.g. coal tar derivatives, chlorinated hydrocarbons)
• oral contraceptive agents
• fatigue and stress
• poor skin hygiene
• chronic irritation (e.g. football helmet straps, backpack straps)
• Easley suggests acne in females is related to low pituitary function at mid-cycle

signs and symptoms

signs and symptoms:
superficial acne:
• comedones: open or closed
• inflamed papules, pustules
• superficial cysts

deep acne:
• pus-filled cysts
• deep inflamed nodules
• scarring: "pock marks"

Both types of acne seem to worsen in the winter.

lab findings:
• (+) food allergies
• low estrogen in some women

course and prognosis

Although the Merck Manual states that "diet has little, if any, effect", many practitioners report significant results from dietary management. Spontaneous remissions of acne do occur, although exacerbations are also frequent. Conventional treatment consists of drug therapy; most of the drugs have "trade-off" complications (tetracycline removes acne but the patient may get yeast infections, colitis, etc.; Retin-A may irritate and cause toxicity reactions).

differential diagnosis

• rosacea
• tuberous sclerosis


footnotes