Bacterial skin infections

Some bacteria live on normal skin and cause no harm, such as some Staphylococcus species, Corynebacterium spp.,Brevibacterium spp and Acinetobacter . Propionibacteria live in the hair follicles of adult skin and contribute to acne.

Some bacteria invade normal skin, broken skin from eczema/dermatitis or wounds (causing wound infection). Bacteria, likeviruses, may also sometimes result in exanthems (rashes). The most common bacteria to cause skin infections are:

• Staphylococcus aureus
  • Folliculitis
  • Furunculosis (boils) and abscesses
  • Impetigo (school sores) and ecthyma
  • Methicillin (meticillin) resistant Staph. aureus
  • Staphylococcal scalded skin syndrome
  • Toxic shock syndrome
  • Tropical pyomyositis
  • Botryomycosis (pyoderma vegetans)
• Streptococcus pyogenes
  • Cellulitis
  • Erysipelas
  • Impetigo
  • Necrotising fasciitis
  • Infectious gangrene
  • Scarlet fever
  • Rheumatic fever, erythema marginatum
• Overgrowth of Corynebacterium spp. (erythrasma, pitted keratolysis and trichomycosis axillaris)

Less commonly, other bacteria may also cause infection with skin signs. These include:

• Neisseria species, cause of gonorrhoea and meningococcal disease
• Erysipelothrix insidiosa, cause of erysipeloid (usually an animal infection)
• Haemophilus species, cause of chancroid and cellulitis in young children
• Helicobacter pylori, a stomach infection, which may be associated with some cases of chronic urticaria and rosacea
• Klebsiella rhinoscleromatis, cause of rhinoscleroma
• Mycoplasma pneumoniae, a cause of pneumonia, causes non-specific erythema, bullous eruptions, urticarial rashes,erythema multiforme, mucositis and rarely, SJS/TEN
• Pseudomonas aeruginosa causes wound infections, athlete's foot, gram negative folliculitis, chronic paronychia (green nail syndrome), spa pool folliculitis and ecthyma gangrenosum
• Calymmatobacterium granulomatis, cause of granuloma inguinale
• Bacillus anthracis, cause of anthrax
• Clostridium perfringens and other species cause gas gangrene
• Treponema species cause syphilis, yaws and pinta
• Bartonella species cause cat scratch fever, bacillary angiomatosis and bartonellosis
• Mycobacterium species cause tuberculosis, leprosy and atypical mycobacterial infections including Buruli ulcer
• Leptospira, cause of leptospirosis, which may cause bleeding into the skin (purpura)
• Nocardia, cause of nocardiosis
• Yersinia pestis, cause of bubonic plague, which causes swollen lymph glands and pustules, ulcers and scabs on the skin
• Serratia marcescens, a facultative anaerobic gram-negative bacillus that may rarely cause skin infections such as cellulitis, abscesses and ulcers; usually in patients with immunodeficiency.
• Fusibacterium species, Bacillus fusiformis, Treponema vincenti and other bacteria may result in tropical ulcer
• Burkholderia species, cause of melioidosis and glanders, in which abscesses may be associated with systemic symptoms.
• Actinomcyes species, cause of actinomycosis, in which granular bacteriosis occurs i.e. abscesses and sinus tracts draining sulphur-yellow granules.
• Vibrio vulnificus, a cause of septic shock characterised by blood-filled blisters.
• Brucella species, cause of brucellosis, a febrile illness caught from unvaccinated animals or their unpasteurised milk.
• Salmonella species, particularly S typhi (typhoid fever)
• Aeromonas found in water rarely causes skin and soft tissue infections

Tick-borne bacterial infections include:

• Lyme disease, due to Borrelia burgdorferi
• Relapsing fever, due to Babesia microti
• Tularaemia, due to Francisella tularensis
• Rickettsial diseases.
• Ehrlichiosis and anaplasmosis

Other conditions sometimes caused by bacterial infection include:

• Kawasaki disease (mucocutaneous lymph node syndrome)
• Pseudofolliculitis barbae (shaving bumps)
• Sarcoidosis
• Scalp folliculitis
• Osler nodes and Janeway lesions (bacterial endocarditis)
• Vaginitis and bacterial vaginosis

What tests should be done?

Laboratory tests for bacterial infections may include:

• Full blood count: bacterial infection often raises the white cell count with increased neutrophils
• C-reactive protein (CRP): elevated >50 in serious bacterial infections
• Procalcitonin: blood test marker for generalised sepsis due to bacterial infection
• Serology: tests 10 days apart to determine immune response to a particular organism
• Polymerase chain reaction (PCR) and ELISA tests for specific organisms
• Blood culture: if high fever >38C
• Swab of inflamed site, eg throat, skin lesions for culture

• Overview of Bacterial Skin Infections

• The skin provides a remarkably good barrier against bacterial infections. Although many bacteria come in contact with or reside on the skin, they are normally unable to establish an infection. When bacterial skin infections do occur, they can range in size from a tiny spot to the entire body surface. They can range in seriousness as well, from harmless to life threatening.

  Many types of bacteria can infect the skin. The most common are Staphylococcus and Streptococcus. Skin infections caused by less common bacteria may develop in people while hospitalized or living in a nursing home, while gardening, or while swimming in a pond, lake, or ocean.

  Some people are at particular risk of developing skin infections. For example, people with diabetes are likely to have poor blood flow, especially to the hands and feet, and the high levels of sugar (glucose) in their blood decrease the ability of white blood cells to fight infections. People who are older, who have human immunodeficiency virus (HIV) or AIDS or other immune disorders, or hepatitis, and who are undergoing chemotherapy or treatment with other drugs that suppress the immune system are at higher risk as well because they have a weakened immune system. Skin that is inflamed or damaged by sunburn, scratching, or other trauma is more likely to become infected. In fact, any break in the skin predisposes a person to infection.

  Prevention involves keeping the skin undamaged and clean. When the skin is cut or scraped, the injury should be washed with soap and water and covered with a sterile bandage. Petrolatum may be applied to open areas to keep the tissue moist and to try to prevent bacterial invasion. Doctors recommend that people do not use antibiotic ointments (prescription or nonprescription) on uninfected minor wounds because of the risk of developing an allergy to the antibiotic. However, an antibiotic ointment is used if an infection develops. Larger areas require antibiotics taken by mouth or given by injection. Abscesses (pus-filled pockets) should be cut open by the doctor and allowed to drain, and any dead tissue must be surgically removed.·          

  ·         Bacterial Skin Infections

  ·         Overview of Bacterial Skin Infections

  ·         Cellulitis

  ·         Erysipelas

  ·         Erythrasma

  ·         Folliculitis and Skin Abscesses

  ·         Hidradenitis Suppurativa

  ·         Impetigo and Ecthyma

  ·         Lymphadenitis

  ·         Lymphangitis

  ·         Necrotizing Skin Infections

  ·         Staphylococcal Scalded Skin SyndromeBacterial Skin Infections

  Leprosy

  Leprosy is caused by a slow-growing type of bacteria calledMycobacteriumleprae (M. leprae). Leprosy is also known as Hansen's disease, after the scientist who discovered M. leprae in 1873.

  Carbuncles

  A carbuncle is a red, swollen, and painful cluster of boils that are connected to each other under the skin.

  Staph Infection

  The infection often begins with a little cut, which gets infected with bacteria. These staph infections range from a simple boil to antibiotic-resistant infections to flesh-eating infections.

  Cellulitis

  Cellulitis is a common infection of the skin and the soft tissues underneath. It happens when bacteria enter a break in the skin and spread.

  Impetigo

  Impetigo is a highly contagious bacterial skin infection. It can appear anywhere on the body but usually attacks exposed areas.

  Boils

  A boil is a skin infection that starts in a hair follicle or oil gland. At first, the skin turns red in the area of the infection, and a tender lump develops. After four to seven days, the lump starts turning white as pus collects under the skin.

  Pilonidal Cyst and Abscess

  A pilonidal cyst occurs at the bottom of the tailbone (coccyx) and can become infected and filled with pus. Once infected, the technical term is pilonidal abscess.

  Fungal Skin Infections

  Fungal Skin Infections

  Fungal infections of the skin are very common and include athlete's foot, jock itch, ringworm, and yeast infections.

  Ringworm

  Worms don't cause ringworm. Rather, this superficial skin infection, also known as tinea, is caused by fungi called dermatophytes.

  Athlete's Foot

  Athlete's foot is a common fungal infection and you don't have to be an athlete to get it. This annoying ailment occurs in boys, girls, men, and women of all ages.

  Candidiasis (Yeast Infection)

  Candidiasis is an infection caused by a group of yeast. There are more than 20 species of Candida, the most common being Candida albicans. These fungi live on all surfaces of our bodies.

  Sporotrichosis

  This fungus is related more closely to the mold on stale bread or the yeast used to brew beer than to bacteria that usually cause infections. The mold is found on rose thorns, hay, sphagnum moss, twigs, and soil. Therefore, the infection is more common among gardeners who work with roses, moss, hay, and soil.

  Fungal Nail Infections

  A fungal nail infection occurs when a fungus attacks a fingernail, a toenail, or the skin under the nail, called the nail bed.

  Viral Skin Infections

  Molluscum Contagiosum

  Molluscum contagiosum is a viral skin infection that causes either single or multiple raised, pearl-like bumps (papules) on the skin.

  Shingles

  Shingles (herpes zoster) results from a reactivation of the virus that also causes chickenpox.

  Chickenpox

  Chickenpox (varicella), a viral illness characterized by a very itchy red rash, is one of the most common infectious diseases of childhood.

  ·         Skin Problems & 

   Skin disorders vary greatly in symptoms and severity. They can be temporary or permament, and may be painless or painful. Some have situational causes, while others may be genetic. Some skin conditions are minor, and others can be life-threatening.

  Common skin conditions include:

  ·         moles

  ·         acne

  ·         hives

  ·         chickenpox

  ·         eczema

  ·         rosacea

  ·         seborrheic dermatitis

  ·         psoriasis

  ·         vitiligo

  ·         impetigo

  ·         warts

  ·         skin cancer

  While most skin disorders are minor, others can indicate a more serious issue. Contact your doctor if you think you might have one of these common skin problems.

  Temporary skin disorders

  Many temporary skin conditions exist, including contact dermatitis and keratosis pilaris.

  Contact dermatitis

  Contact dermatitis is one of the most common occupational illnesses. The condition is often the result of contact with chemicals or other irritating materials. These substances can trigger a reaction that causes the skin to become itchy, red, and inflamed. Most cases of contact dermatitis aren’t severe, but they can be rather itchy. Topical creams and avoiding the irritant are typical treatments.

  Keratosis pilaris

  Keratosis pilaris is a minor condition that causes small, rough bumps on the skin. These bumps usually form on the upper arms, thighs, or cheeks. They’re typically red or white and don’t hurt or itch. Treatment isn’t necessary, but medicated creams can improve skin appearance.

  Permanent skin disorders

  Some chronic skin conditions are present from birth, while others appear suddenly later in life.

  The cause of these disorders isn’t always known. Many permanent skin disorders have effective treatments that enable extended periods of remission. However, they’re incurable and symptoms can reappear at any time. Examples of chronic skin conditions include:

  ·         rosacea, which is characterized by small, red, pus-filled bumps on the face

  ·         psoriasis, which causes scaly, itchy, and dry patches

  ·         vitiligo, which results in large, irregular patches of skin

  Skin disorders in children

  Skin disorders are common in children. Children can experience many of the same skin conditions as adults. Infants and toddlers are also at risk for diaper-related skin problems. Since children have more frequent exposure to other children and germs, they may also develop skin disorders that rarely occur in adults. Many childhood skin problems disappear with age, but children can also inherit permanent skin disorders. In most cases, doctors can treat childhood skin disorders with topical creams, medicated lotions, or condition-specific drugs.

  Common childhood skin disorders include:

  ·         eczema

  ·         diaper rash

  ·         seborrheic dermatitis

  ·         chickenpox

  ·         measles

  ·         warts

  ·         acne

  ·         fifth disease

  ·         hives

  ·         ringworm

  ·         rashes from bacterial or fungal infections

  ·         rashes from allergic reactions

  Symptoms of skin disorders

  Skin conditions have a wide range of symptoms. Symptoms on your skin that appear due to common problems aren’t always the result of a skin disorder. Such symptoms can include blisters from new shoes or chafing from tight pants. However, skin problems that have no obvious cause may indicate the presence of an actual skin condition that requires treatment.

  Skin irregularities that are typically symptoms of a skin disorder include:

  ·         raised bumps that are red or white

  ·         a rash, which might be painful or itchy

  ·         scaly or rough skin

  ·         peeling skin

  ·         ulcers

  ·         open sores or lesions

  ·         dry, cracked skin

  ·         discolored patches of skin

  ·         fleshy bumps, warts, or other skin growths

  ·         changes in mole color or size

  ·         a loss of skin pigment

  ·         excessive flushing

  Causes of skin disorders

  Common known causes of skin disorders include:

  ·         bacteria trapped in skin pores and hair follicles

  ·         fungus, parasites, or microorganisms living on the skin

  ·         viruses

  ·         a weakened immune system

  ·         contact with allergens, irritants, or another person’s infected skin

  ·         genetic factors

  ·         illnesses affecting the thyroid, immune system, kidneys, and other body systems

  Numerous health conditions and lifestyle factors can also lead to the development of certain skin disorders. Some skin conditions have no known cause.

  Inflammatory bowel disease

  Inflammatory bowel disease is a term for a group of intestinal disorders that cause prolonged inflammation of the digestive tract. These bowel-related disorders often cause skin problems. The drugs used to treat these diseases can cause certain skin conditions, such as:

  ·         skin tags

  ·         anal fissures

  ·         stomatitis

  ·         vasculitis

  ·         vitiligo

  ·         allergic eczema

  Diabetes

  Many people with diabetes experience a skin problem as a result of their condition at some point. Some of these skin disorders only affect people with diabetes. Others occur more frequently in people with diabetes because the disease increases the risk for infection and blood circulation problems. Diabetes-related skin conditions include:

  ·         bacterial infections, such as boils, styes, and folliculitis

  ·         fungal infections, such as athlete’s foot, ringworm, and yeast infections

  ·         acanthosis nigricans

  ·         diabetic blisters

  ·         diabetic dermopathy

  ·         digital sclerosis

  Lupus

  Lupus is a chronic inflammatory disease that can damage the skin, joints, or organs inside the body. Common skin problems that occur from lupus include:

  ·         round lesions on the face and head

  ·         thick, red, scaly lesions

  ·         red, ring-shaped lesions on body parts exposed to sunlight

  ·         flat rash on the face and body that looks like a sunburn

  ·         red, purple, or black spots on fingers and toes

  ·         sores inside the mouth and nose

  ·         tiny red spots on the legs

  Pregnancy

  Pregnancy causes significant changes in hormone levels that may lead to skin problems. Pre-existing skin problems may change or get worse during pregnancy. Most skin conditions that arise during pregnancy go away after the baby is born. Others require medical attention during pregnancy.

  Common skin conditions caused by pregnancy include:

  ·         stretch marks

  ·         melasma

  ·         pemphigoid

  ·         pruritic urticarial papules and plaques

  ·         dermatitis

  Stress

  Stress can cause hormonal imbalances, which may trigger or aggravate skin disorders. Stress-related skin problems include:

  ·         eczema

  ·         psoriasis

  ·         acne

  ·         rosacea

  ·         ichthyosis

  ·         vitiligo

  ·         hives

  ·         seborrheic dermatitis

  ·         alopecia areata

  ·         hemangiomas

  Sun

  The sun can cause many different skin disorders. Some are common and harmless, while others are rare or life-threatening. Knowing if the sun causes or worsens your skin disorder is important for treating it properly.

  Sunlight exposure may cause or aggravate the following conditions:

  ·         moles

  ·         wrinkles

  ·         sunburn

  ·         actinic keratosis

  ·         skin cancer

  ·         photosensitivity

   

  Bacterial Skin Infections: Impetigo and MRSA

  What kinds of bacteria can cause contagious skin infections?

  Certain bacteria commonly live on the skin of many people without causing harm. However, these bacteria can cause skin infections if they enter the body through cuts, open wounds, or other breaks in the skin. Symptoms may include redness, swelling, pain, or pus.

  How serious are bacterial skin infections?

  While many bacterial skin infections are mild and easily treatable, some can become very serious and even life threatening. In addition, some bacterial infections can be spread to others. This is why prevention is so important.

  What are the two most common bacteria that cause skin infections?

  1. Group A Streptococcus (GAS), often called "strep."
  2. Staphylococcus aureus, commonly called "staph."

  Impetigo

  What is impetigo?

  Impetigo is a common bacterial skin infection caused by Group A Streptococcus (GAS) or "strep."

  What is Group A Streptococcus (GAS)?

  Group A Streptococcus (GAS) or "strep" is a common bacterium (bacterium is the singular form of the plural, bacteria) that is found on the skin or in the throat ("strep throat"). People can carry GAS and have no symptoms of illness or they may develop relatively mild skin infections, including impetigo.

  How does impetigo spread?

  Group A Streptococcus (GAS) or "strep" can be transmitted through direct person-to-person contact with someone who has the infection. GAS can also be picked up indirectly through contact with an item (such as a wrestling mat, gear, towel, razor, or cell phone) that is contaminated with the bacterium.

  What are the symptoms of impetigo?

  • Symptoms usually began 1-3 days after infection.
  • Sores (lesions) begin as small red spots, usually on the face (especially around the nose and mouth), but can appear anywhere on the body.
  • The sores are often itchy, but usually not painful.
  • The sores develop into blisters that break open and ooze fluid -- this fluid contains infectious bacteria that can infect others if they have contact with it.
  • After a few days, the ruptured blisters form a flat, thick, honey-colored (yellowish-brown) crust that eventually disappears, leaving red marks that heal without scarring.
  • There may be swollen glands (enlarged lymph nodes), but usually no fever.
  • Click here to view a photograph of impetigo on the face from DermAtlas.

  What should athletes do if they think they have impetigo?

  While mild cases of impetigo may be treated without seeing a health care provider, athletes are recommended to have a medical professional determine what type of infection they have, how to treat it, and if it is contagious. If the infection is contagious, athletes should not practice or compete until their medical provider clears them to return.

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  Methicillin-Resistant Staphylococcus aureus (MRSA)

  What is Staphylococcus aureus?

  Staphylococcus aureus ("staph") is a bacterium that is carried on the skin or in the nose of approximately 25% to 30% of healthy people without causing infection -- this is called colonization. Staph bacteria are one of the most common causes of skin infections in the U.S. Most of these skin infections are minor (such as pimples and boils), are not spread to others (not infectious), and usually can be treated without antibiotics. However, some staph bacteria are resistant to certain antibiotics -- one type is called MRSA.

  What is MRSA?

  MRSA stands for methicillin-resistant Staphylococcus aureus. MRSA is a staph bacterium that certain antibiotics in the penicillin family should be able to treat, but cannot. When the infection is resistant to the medication, it is called resistance. However, other non-penicillin antibiotics can effectively treat most MRSA infections.

  MRSA Infection on Arm

  What causes antibiotic resistance?

  Most resistance to antibiotics develops from taking them improperly. Examples are:

  • Incomplete use: Not finishing the entire antibiotic prescription (often because people start to feel better and stop taking the medication).
  • Inappropriate use: Taking antibiotics for a viral infection (antibiotics do NOT treat viral infections such as colds or the flu).
  • Unnecessary use: Taking antibiotics "just in case" (for example, taking them prior to a vacation or special event to try to prevent illness).

  It is important to take prescription medication only when prescribed for you by a health professional and to take all the medicine even if you feel better before you have completed the prescription.

  How serious is MRSA?

  Although health care providers can treat most MRSA skin infections in their offices, MRSA can be very serious and even cause death. MRSA can cause pneumonia or severe infections of the blood, bones, surgical wounds, heart valves, and lungs. MRSA can be fatal if not identified and treated with effective antibiotics.

  How does someone get MRSA infection?

  Most often, MRSA is transmitted by direct skin-to-skin contact with someone who has the infection.

  MRSA can be spread by indirect contact too (for example contact with a mat that has infected drainage on it or by sharing a towel or cell phone with someone who has MRSA). Because of this, never share personal hygiene and health items.

  Where on the skin does MRSA appear and what are the symptoms?

  MRSA infections commonly occur where there is a break in the skin (for example, a cut or wound), especially in areas covered by hair (for example, the beard area, back of the neck, armpit, groin, legs, or buttocks)

  MRSA may look like a bump on the skin that may be red, swollen, warm to the touch, painful, filled with pus, or draining. The pus or drainage contains the infectious bacteria that can be spread to others. People with MRSA may have a fever.

  MRSA Infection on Thigh

  •