The different types of acne are typically clumped together in one, generalized category of skin condition. However, each individual type varies in appearance, and has its own set of characteristics. Here is an in-depth look at the most common forms that can help you better understand and treat each individual symptom.
Open Comedo (Blackhead)
Open comedones, more commonly known as blackheads, are partially clogged pores or follicles resulting from an accumulation of excess sebum, which are oils naturally secreted by the skin. Usually, bacteria, dead skin cells and keratin are also trapped in the pore. This sebum mixture, same as that of a closed comedo (whitehead), oxidizes as it is exposed to the air and turns dark in color. Thus, its physical appearance is often characterized as raised black or dark yellow plugs on the skin. Upon extraction, the sebum plugs are fixed structures that are yellowish brown in color.
- Open comedones are usually non-inflammatory.
- Blackheads most commonly appear on (but are not limited to) the nose and buttocks.
- While they do not necessarily cause discomfort, untreated blackheads may grow in size and enlarge pores as they stretch the surrounding skin.
Closed Comedo (Whitehead)
Closed comedones, more commonly known as whiteheads, are completely blocked pores or follicles with an accumulation of excess sebum, bacteria, dead skin cells and keratin. The composition of the sebum mixture is the same as that of open comedo (blackheads). Since whiteheads lack the microscopic openings that blackheads have, the sebum mixture is not exposed to the air and does not oxidize. Thus, they remain a white, sometimes yellowish, color.
- The physical appearance is characterized as a small, white bump, and upon extraction, the sebum is a fixed structured plug like that of a blackhead.
- Closed comedones are also usually non-inflammatory.
- Whiteheads can appear anywhere on the skin, and should not be confused with milia (keratin-filled cysts with a similar physical appearance).
Papules (Red Bumps/Pimples)
Papules are characterized as red, inflamed bumps without heads, as they are not yet filled with pus. Normally, untreated comedones may worsen into papules when an infected follicular wall erupts, allowing the sebum and bacteria mixture to penetrate the surrounding skin. As white blood cells rush to the erupted follicle to fight infection, inflammation occurs. If left untreated, papules may worsen into pustules.
Pustules (Red Bumps With A White Head)
When papules are left untreated for several days, the accumulation of white blood cells (also known as puss) will gradually move to the surface of the skin. Thus, pustules are characterized as blemishes with an inflamed, red border and a yellowish or white puss-filled center. One characteristic that distinguishes pustules from whiteheads is the inflammation; pustules have a red, irritated border while whiteheads are generally non-inflammatory. Pustules are also the standard "pimples" or "zits" that most people refer to, and may be tender to the touch.
Nodules And Cysts
Nodular and cystic acne are large, "under the skin" forms of acne vulgaris and are considered more severe than the previous types. While nodules are deep, firm bumps, cysts are deep, soft bumps filled with fluid. Inflammation is common for both, and they are also painful to the touch. Nodules and cysts are formed when an inflamed follicle completely collapses or explodes under the skin. The inflammatory sebum mixture then engulfs the surrounding follicles and severely infects surrounding pores.
Squeezing and picking these blemishes are generally discouraged, as incorrect treatment can result in an even deeper and widespread infection. It can also lead to prolonged inflammation, skin trauma and irreversible scarring. If left unresolved, nodular and cystic acne can cause recurring episodes at the same location. It is important to see a dermatologist for treatment of nodules and cystic acne to minimize skin trauma and scarring.
Extremely Severe Acne
Extremely severe forms of acne vulgaris are rare, but can lead to serious scarring of the skin and even disfigurement. Two common types of extremely severe acne vulgaris include the following:
Acne conglobata is more common in males than in females, and it can happen between the ages of 18 and 30. Its physical appearance is often characterized by extremely inflamed, large, deep, interconnected nodules and abscesses that stay active for many years. It is most commonly found on the face, chest, back, buttocks, upper arms and thighs.
This condition usually begins with untreated patches of widespread blackheads that worsen to severe cases of nodular and cystic acne. Such nodules and cysts may then continue to rupture and interconnect to create recurring lesions and abscesses. If left untreated, acne conglobata may lead to irreversible skin damage and severe scarring, even disfigurement.
Acne fulminans, also known as acute febrile ulcerative acne, may take place if treatment for acne conglobata is unsuccessful. The affected individual will develop pain and inflammation in the joints in addition to dermatological problems present in acne conglobata. Swelling of lymph nodes in the neck, as well as extreme weight loss and muscle atrophy, may occur. At this point, it is imperative to seek medical treatment, as hospitalization may be needed. Acne fulminans is also considered to be an immunologically induced disease.