Acne Vulgaris

Key Points
Acne is a disorder of the pilosebaceous unit, which is composed of a hair follicle and associated oil gland. The follicular opening becomes clogged with a plug containing dead skin cells and oil. The occluded follicle then becomes inflamed, likely due to the activity of a bacteria known as P. acnes.

Clinical features are well known and include whiteheads (closed comedones), blackheads (open comedones), inflamed red papules and pustules, and occasionally deeper cysts or nodules

Factors leading to the development of acne include:
-Androgen hormone activity causing overactive sebaceous glands with resultant increased oil production
-Comedone (pore blockage) formation, which is affected strongly by genetic factors
-Overgrowth of P. acnes bacteria

Commonly appears on the face and shoulders

Most common in teenagers, but can occur at any age. The higher levels of sex hormones during puberty are the initiating factor leading to increased sebum (oil) production.

Acne is a very common skin condition in which pores become clogged with sebum (oil) and keratin (skin cell components). This is most often triggered by an increase in the production of sex hormones during puberty. However, acne may occur at any age. The plugged pores (comedones) are more prone to overgrowth of the skin bacteria, P. acnes, which will often result in an inflammatory response within the follicle. This leads to the develoment of papules, pustules, nodules or cysts. Acne often runs in families and may be triggered by hormonal changes related to menstruation, pregnancy, birth control or stress. Acne may be triggered by the use of oily cosmetic products, the use of certain drugs including steroids, hormone replacements, and phenytoin, or being exposed to high levels of humidity and sweating.

The blockage of the pore, called the plug or comedone, can manifest in several different ways. It may appear light (whitehead) or dark (blackhead). If the plug ruptures, the material inside may spread to the surrounding skin, causing it to become inflamed. Inflammation deep in the skin tissue can lead to the formation of cysts. Acne can also lead to facial scarring or changes in skin color.

Nodulocystic Acne

Key Points
A severe type of acne slightly more common in men
Characterized by large cysts, several centimeters in diameter
Cysts may occur singly, or affect widespread areas of the face, neck, scalp, back, chest and shoulders

In nodulocystic acne, the formation of large cysts leads to deep tissue inflammation, resulting in tender nodules with sinus tracts that drain pus. This acne subtype often leads to severe scarring.

Acne conglobata is the most severe form of nodulocystic acne. The inflammatory cysts coalesce(grow together) forming multiple draining sinus tracts. Very thick scars (hypertrophic scars) and keloid type scar may result.

Differential Diagnosis (Other conditions with similar appearance)
Rosacea
Perioral Dermatitis
Acneiform Drug eruptions
Hidradenitis supporitiva

Diagnosis
Key Points
Diagnosis based on skin appearance
Testing is not required, although cultures are sometimes useful to evaluate for gram negative folliculitis, a complication of antibiotic use in acne.

Acne is generally diagnosed based on appearance, then further graded by severity, based on the number of total lesions. Under 30 total lesions is considered mild, with a moderate case consisting of 30 to 125 lesions. Severe cases can consist of greater than 125 lesions or the appearance of more than 5 cysts in the affected area.

Treatment

Many treatment options exist, though there is no cure for acne
Health care professionals may prescribe topical or oral treatments in moderate or severe cases

OTC Options: Acne medications containing Benzoyl peroxide, sulfur, resorcinol, or salicylic acid

While there is no cure for acne, many treatment options exist to lessen its effects. Self care options include keeping the affected areas clean with a mild, non-drying soap, avoiding squeezing the pimples, and avoiding oil based cosmetics. OTC topical acne medications (many containing benzoyl peroxide or salicylic acid) can help by killing bacteria, drying excess oil, and causing breakdown of the comedone (comedolysis).

In more substantial cases, health care professionals may prescribe medications. These include both topical and oral options. Topical perscription options include such as topical antibiotics such as clindamycin as well as topical retinoids such tretinoin or adapalene. Sodium sulfacetamide is also an excellent topical option, available as both a cream or wash. Dapsone is another topical drug that has some utility, particular in cases with a significant pustular component. Combining these agents is also quite effective, such as using a benzoyl peroxide wash with a topical retinoid applied in the evening. There are a number of combination topical trade drugs as well, many of which combine a retinoid with a topical antibiotic such as clindamycin.

Dermatologists may also use various oral therapies for acne, including antibiotics, retinoids, and for women, hormonal directly medications. Antibiotics work not only by killing P. acnes, but also help to control inflammation. Tetracycline antibiotics such as doxycycline or minocycline are often the choice here, but some dermatologists use bactrim, azithromycin, and others as well.

Isotretinoin is an excellent choice for severe or scarring acne, but can cause some problems. It is a potent teratogen and can cause severe dryness. A full discussion of isotretinoin is available on our website.

Hormonal therapies are an excellent option for females, including spironolactone and oral contraceptive pills, especially those with spironolactone-like effects, such as drospirenone.