Types of Acne: Differences, Treatments and Prevention

• Acne can appear in many forms including comedones, pimples, cysts and nodules.
• To avoid scarring, do not pick or squeeze any type of acne lesion. 
• Acne treatment depends on the type of acne and its severity.
• Some severe types of acne such as cysts and nodules require professional treatment.

Acne is an umbrella term that refers to different skin issues that result from clogged pores. Acne vulgaris, the most common form of acne, encompasses a number of skin concerns including pimples and blackheads.

Acne usually appears on the face, forehead, shoulders, chest and upper back as these are the areas where pores and oil-producing glands are concentrated.

What Is Acne?

Acne is a skin condition that begins when hair follicles, also known as pores, become clogged by dead skin cells or other debris. 

Each pore contains a sebaceous gland that produces an oily substance known as sebum, which lubricates hair and moisturizes skin. However, when a pore becomes filled with debris, this sebum becomes trapped and hardens, forming a plug. 

This plug can become infected by a bacterium known as Propionibacterium acnes, leading to swelling and the formation of visible signs of acne.   

Factors such as the size of your pores and your skin type can increase the likelihood of pore blockages and acne. Hormonal activity, diet and stress levels can also contribute to acne outbreaks.

Types of Acne

All acne types begin with a blocked pore, however variations in this blockage and the bodies response to them, result in different types of acne. 

The four main manifestations of acne are, in order of severity: comedones, pimples, cysts and nodules. Each type of acne differs in appearance, progression and required treatment. 

Comedones

Comedones are the most common type of acne and can lead to other forms developing. Comedones occur when a pore becomes clogged by debris and bacteria begin to cluster. 

Blackheads

If the blockage remains exposed to air it will darken and form an open comedone, commonly known as a blackhead. Blackheads are the most basic and common form of acne, and may become raised as oil builds up beneath it. 

Blackheads are typically easy to prevent and treat with over-the-counter (OTC) cleansers and exfoliators. Tools such as comedone extractors can also help eliminate blackheads at home. 

Whiteheads

In cases where skin grows over a blockage and seals it from air, a closed comedone will form, typically referred to as a whitehead. This closed comedone is an airtight pocket of skin containing bacteria; if popped, this bacteria can spread to surrounding pores, worsening cases of acne.

As with blackheads, whiteheads can often be treated and prevented through the use of OTC topical products.

Pimples

Like other forms of acne, pimples occur as a result of clogged oil glands. Pimples typically form as a result of overactive oil glands that reside at the base of hair follicles – usually on the face, chest, shoulders or back.

Pimples form when excess oil combines with bacteria and inflammation occurs, indicated by the appearance of pus. 

Papules

Papules are inflamed pimples that present as red or pink bumps on the skin. These pimples are not necessarily painful but may be sensitive to the touch. Papules should never be picked or squeezed as this can cause scarring.

Pustules

Pustules are similar in appearance to whiteheads except the bumps are surrounded by a red ring of inflammation. Pustules are filled with pus and may resemble larger whiteheads. Like papules, pustules should not be picked or squeezed as this may lead to scarring.

Cysts

A cyst is a large lesion filled with pus that may resemble a boil. Skin cysts form when pore blockages occur deep within a hair follicle and an infection ensues that damages deeper layers of skin. Oil that is normally secreted becomes trapped beneath the skin and develops into a pouch known as a cyst.  

Cysts are often painful and are a severe form of acne that requires treatment by a dermatologist.

Nodules

Nodules are large, inflamed bumps that feel solid to the touch. They form when the P. acnes bacteria becomes trapped inside a pore and causes an infection that reaches the deeper layers of skin. This infection causes hard and painful nodules to appear beneath the skin.

Like cysts, nodules require treatment from a dermatologist.

Acne Severity

The severity of acne can vary markedly from a few minor blemishes to severely inflamed lesions. One of the most significant factors that determines the severity of acne is the strain of bacteria that clusters at a clogged pore. Different bacterial strains can produce varying severities of acne. 

While there are dozens of acne assessment methods used by dermatologists to classify the severity and extent of acne, there is currently no universally accepted classification system.

These assessment systems take into account various aspects of acne such as its location on the body, the extent of its coverage and the number of visible lesions.

For practical purposes, acne has often been classified on a four-point scale of severity as being either clear, mild, moderate or severe, with clear representing acne-free skin. Acne has also been classified as either inflammatory or noninflammatory. The latter refers primarily to the mild comedonal acne forms such as blackheads and pimples; the former is characterized by red and swollen skin.

Mild acne

Acne vulgaris  is considered to be mild if there are less than 20 blackheads or whiteheads; less than 15 pimples; or less than 30 lesions combined in an area.

Dermatologists typically recommend treating mild acne with topical OTC treatments.

Moderate acne

Moderate acne is characterized by the presence of more than 20 blackheads or whiteheads; more than 15 pimples; or more than 30 total lesions. Dermatologists usually prescribe topical medication to treat moderate acne. 

Severe acne

Severe acne usually consists of multiple breakouts over many areas of skin, including the face, back, chest, neck or jawline. It often reaches into the deeper layers of the skin; it can be painful and leave serious scarring when it resolves. 

Some forms of severe acne include nodules, cysts or a combination of the two. Severe acne is often also accompanied by whiteheads, blackheads or both.     

Other forms

Acne mechanica

Often referred to as “sports-induced acne” because it affects so many athletes, acne mechanica occurs when skin is subjected to pressure, heat and friction. This often occurs when wearing sports gear such as a baseball hat, helmet, shin guards or other protective equipment.

This form of acne can also be triggered by tight-fitting clothes, bra straps and the straps of backpacks.

To prevent acne mechanica, individuals can wear a garment that absorbs sweat underneath their sports gear and shower immediately after any activity. Those wearing tight-fitting clothes can opt for looser options, particularly in hot weather.

Acne conglobata

Acne conglobata typically appears on the arms, chest, buttocks and neck and often leads to scarring. This severe form of acne consists of numerous inflamed nodules that are connected beneath the skin. It is more prevalent in men and can be a result of steroid or testosterone use. 

If you suspect that you have this form of acne, you should see a dermatologist as soon as possible in order to mitigate the potential scarring risks.

Nodulocystic acne

Nodulocystic acne is characterized by numerous inflamed nodules and cysts that often appear purple or red. Like acne conglobata, nodulocystic acne often leads to scarring, but this may be minimized by seeing a dermatologist. 

Through injections of corticosteroids cysts and nodules many be reduced in size and any associated pain can be alleviated.

Acne Treatments

The treatment for any particular form of acne will depend on its severity. Dermatologists typically recommend treating mild acne with topical OTC treatments and will usually prescribe a combination of topical and oral medication to treat moderate to severe acne.

Topical treatments

Topical acne treatment, also called topical therapy, refers to medications in the form of creams and gels applied to the skin.

OTC treatments containing ingredients such as salicylic acid (SA) and benzoyl peroxide are often effective at treating mild acne such as comedones and pimples. 

Prescription topical acne treatments such as retinoid creams may be effective in the treatment of moderate acne. Topical treatments may also be prescribed in conjunction with oral acne treatments for a tailored acne regimen. These treatments should be used as directed in order to avoid potential risks and side effects. 

Systemic treatments

Systemic treatments are those taken orally. These include medications such as tetracycline, doxycycline and erythromycin, all of which attack bacteria and minimize inflammation. Due in part to their potential side effects, these treatments are typically reserved for moderate or severe acne.

Additional systemic treatments include oral contraceptives, which can be effective in reducing acne for some women; one ingredient is spironolactone, which targets the overproduction of the hormone androgen. 

Isotretinoin, another oral treatment, is considered an option of last resort. It is only used for severe cases of cystic acne and for people who have not responded to other treatment. Ongoing appointments with a dermatologist are usually required while using isotretinoin in order to monitor its effects.

Treatment procedures

In some cases, acne may require in-office treatment by a dermatologist. These can include laser therapy, light therapy and chemical peels, depending on the type and severity of the acne. 

Cysts and nodules may require drainage and extraction when topical treatment options fail. During these procedures, a dermatologist makes a surgical incision in the affected area to drain fluids and pus from the cyst or nodule. 

A dermatologist may also inject a cyst or nodule with a diluted corticosteroid. The anti-inflammatory properties of corticosteroids can help decrease the inflammation associated with these types of acne in as little as 24 hours.   

Takeaway

Acne treatment will depend on what type of acne you have and whether it is mild, moderate or severe. Comedones, pimples, cysts and nodules each require their own specialized treatments, from OTC topicals to prescription oral medications and procedures. 

If you are unsure of which type of acne you have or if OTC treatments are not improving the condition of your skin, seek professional help. A board-certified dermatologist is best equipped to analyze your situation and provide an acne treatment that is suited to your acne type.