9 Common Bacterial Skin Infections

Bacterial skin infections are fairly common. They can be mildly annoying to life-threatening. Most bacterial infections are caused by Staphylococcus aureus (staph) or Streptococcus pyogenes (the same bacteria responsible for strep throat).

Bacterial infections can look different ways depending on where they are located, the type of bacteria, and a person's age. Most can be treated by your doctor.

However, you may need to see a dermatologist or rheumatologist for more complicated infections. In the most serious cases, a bacterial infection can spread to the bloodstream. This is known as septicemia, and it can be life-threatening.

Here is a rundown of the nine most common bacterial infections and how to identify them.

Cellulitis

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Cellulitis

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Cellulitis affects the two deepest layers of the skin—the dermis and the subcutaneous tissue. It often appears as a swollen, red area on the skin and feels tender and hot when touched.

Cellulitis usually occurs when the skin is broken, such as near ulcers, bruises, burns, or recent surgical wounds. While many types of bacteria can cause cellulitis, Staphylococcus and Streptococcus are the most common culprits.

If the cellulitis spreads to your lymph nodes and bloodstream, it can be deadly. Seek medical help immediately if you suspect you have this infection.

Erysipelas

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Erysipelas

 DermNet / CC BY-NC-ND

Erysipelas infects the top two layers of the skin. It is commonly known as "St. Anthony's Fire" because of the intense, burning sensation that occurs with it.

Symptoms include extreme redness, swelling, and a sharply defined border between the normal and infected skin. It is similar in appearance to cellulitis. However, cellulitis occurs in the lower layers of the skin.

Streptococcus bacteria cause erysipelas. Minor things like athlete's foot or eczema can lead to erysipelas by causing a break in the skin. It can also occur when bacteria spread to the nasal passages following a nose or throat infection.

Bacterial Folliculitis

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Bacterial Folliculitis

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Bacterial folliculitis is a relatively common infection of the hair follicles. It is usually caused by a fungus, ingrown hair, or blockages from moisturizers or other products applied to the skin. Shaving or plucking hairs can also increase risk.

Symptoms of bacterial folliculitis include tiny, red bumps or white-headed pimples filled with pus. This infection tends to occur more often in people with acne than those who have clearer skin.

While bacterial folliculitis usually heals on its own, more severe cases may require antibiotics. Left untreated, folliculitis can cause permanent hair loss.

Hot Tub Folliculitis

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Hot Tub Folliculitis

 Joel Carillet / Getty Images

Hot tub folliculitis causes pus-filled bumps and an itchy red rash. These symptoms come on a few hours to several days after exposure to the bacteria that cause it.

It is sometimes called “Pseudomonas folliculitis” or “Jacuzzi folliculitis" because it is contracted through contaminated whirlpools and hot tubs (especially wooden ones). You can also become infected through water slides, physiotherapy pools, or even loofah sponges.

Hot tub folliculitis typically shows up on the chest or groin, where water and bacteria have been trapped for a period of time. It is caused by the Pseudomonas aeruginosa bacteria, which can even survive in chlorinated water. This makes it tougher to kill.

Not surprisingly, children are more prone to hot tub folliculitis because their skin is thinner and they tend to stay in the water longer than adults.

Hot tub folliculitis is also more common in people with acne or dermatitis. That's because these conditions can allow the bacteria to get into the skin.

Furuncles

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Furuncles

Mahdouch / Wikimedia Commons / CC BY 1.0 

A furuncle, more commonly known as a boil, is a painful infection around a hair follicle. It begins as a red lump, which may be tender, and rapidly fills with pus as it gets bigger. If left untreated, a furuncle can develop into an abscess.

Unlike folliculitis, which also involves infection of a hair follicle, a furuncle is an infection of the entire pilosebaceous unit. Pilosebaceous units are made up of a hair shaft, follicle, sebaceous gland, and arrector pili muscle (a bundle of small muscle fibers attached to a hair follicle). These are located throughout the body (except on the palms, soles of the feet, and lower lip).

Furuncles are commonly found on the face, neck, armpits, buttocks, and thighs. Applying warm compresses can help drain a furuncle of pus. But in severe cases, your doctor may need to lance (puncture) it with a sterile instrument to allow it to drain.

Carbuncles

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Carbuncles

Drvgaikwad/Wikimedia Commons / CC BY 3.0 

A carbuncle is a cluster of several furuncles closely packed together. It can be as large as 4 inches across and usually has one or more openings where pus may ooze onto the skin. The infection may also cause a fever, general weakness, and exhaustion.

Carbuncles usually develop on the back, thighs, or back of the neck. The infection tends to be deeper and more severe than those caused by furuncles. The most common cause of a carbuncle is staph bacteria.

The risk of scarring is higher with a carbuncle infection, and it may take longer to develop and get better than furuncles. For this reason, carbuncles often require medical attention. In addition, they are contagious and can spread to other parts of the body and other people.

Impetigo

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Impetigo

 CFCF / Wikimedia Commons / CC BY 4.0

Impetigo is a bacterial infection of the top layer of epidermal skin. It is highly contagious and more commonly seen in children than adults. Caused by Streptococcus and Staphylococcus, the impetigo rash is covered by a honey-colored crust.

The sores from this bacterial infection usually occur around the nose and mouth. But it can spread to other parts of the body through skin-to-skin contact, clothing, and towels. Impetigo is usually treated with topical antibiotics.

Erythrasma

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Erythrasma

 DermNet / CC BY-NC-ND

Erythrasma is a superficial skin infection caused by the Corynebacterium minutissimum bacteria. At the beginning, symptoms include well-defined pink patches of skin covered with fine scales and wrinkling. The rash becomes red, then brown and scaly.

Erythrasma develops in areas where skin touches skin, such as the armpits, groin, or between the toes. Due to its location and appearance, it's often confused with fungal infections like athlete's foot and jock itch.

People with erythrasma usually have no symptoms. But mild itchiness or burning may be present, especially if the infection is in the groin area.

Erythrasma commonly develops in warm, humid climates. Other risk factors include:

  • Poor hygiene
  • Sweating
  • Obesity
  • Diabetes
  • Older age
  • Poor immune function

MRSA Skin Infections

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MRSA Skin Infection

CDC / Bruno Coignard, M.D.; Jeff Hageman, M.H.S. / Wikimedia Commons / Public Domain 

Methicillin-resistant Staphylococcus aureus (MRSA) is a serious bacterial infection that is resistant to standard antibiotic treatment. It will often cause a mild, blister-like sore on the skin.

Sometimes MRSA leads to serious infections. In these cases, it can spread through the bloodstream and infect other organs, such as the lungs or urinary tract.

The symptoms of an MRSA infection depend on the part of the body that is infected and may include redness, swelling, pain, pus, or fever. Some MRSA infections look like other bacterial skin infections and can even be confused with a spider bite.

Laboratory tests are usually required to diagnose MRSA accurately. If left untreated, MRSA can easily spread from person to person and may be contracted in the hospital following surgery.

Summary

Bacterial infections of the skin are common, and they can be hard to tell apart. While most aren't dangerous, they do need treatment, and some can lead to serious and even life-threatening complications.

If you notice what you think might be a skin infection on yourself or a loved one, be sure to see a doctor to get the right diagnosis and treatment.

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10 Sources
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  1. Ma XY, Tian LX, Liang HP. Early prevention of trauma-related infection/sepsisMil Med Res. 2016;3:33. doi:10.1186/s40779-016-0104-3

  2. Sullivan T, de Barra E. Diagnosis and management of cellulitisClin Med (Lond). 2018;18(2):160–163. doi:10.7861/clinmedicine.18-2-160

  3. Michael Y, Shaukat NM. Erysipelas. In: StatPearls. Updated December 20, 2019.

  4. Ogunbiyi A. Pseudofolliculitis barbae; current treatment optionsClin Cosmet Investig Dermatol. 2019;12:241–247. doi:10.2147/CCID.S149250

  5. Bennett J, Blaser M. Chapter 221 - Pseudomonas aeruginosa and ther Pseudomonas species. In: Mandell, Douglas, And Bennett's Principles And Practice Of Infectious Diseases. 8th ed. Philadelphia: Saunders; 2015. doi:10.1016/B978-1-4557-4801-3.00221-6

  6. National Center for Biotechnology Information, U.S. National Library of Medicine. Boils and carbuncles: How are boils treated? Updated June 14, 2018.

  7. MedlinePlus. Carbuncle. Updated April 16, 2019.

  8. MedlinePlus. Impetigo. Updated April 30, 2019.

  9. Kaur D, Chate S. Study of antibiotic resistance pattern in methicillin resistant Staphylococcus aureus with special reference to newer antibioticJ Glob Infect Dis. 2015;7(2):78. doi:10.4103/0974-777x.157245

  10. Bhattacharya S, Pal K, Jain S, Chatterjee SS, Konar J. Surgical site infection by methicillin resistant Staphylococcus aureus- on decline? J Clin Diagn Res. 2016;10(9):DC32–DC36. doi:10.7860/JCDR/2016/21664.8587