Some bacteria live on normal skin and cause no harm. Some bacteria invade normal skin, broken skin from eczema/dermatitis or wounds (causing wound infection. The most common bacterial skin infections are folliculitis, furunculosis (boils) and abscesses, impetigo and ecthyma.
Bacterial infections are treated with antibiotics. These are available for localised topical use (creams, gels, solutions), eg antibiotics for acne, or as systemic treatment as tablets, capsules and intramuscular or intravenous injections.
Bacterial folliculitis (boil): Maceration and occlusion , waxing or other forms of epilation, Friction from tight clothing, atopic dermatitis, acne or other follicular skin disorder, use of topical corticosteroids, anaemia, obesity, diabetes, and other chronic illness can predispose to folliculitis.
Impetigo: It is a common acute superficial bacterial skin infection (pyoderma). It is characterised by pustules and honey-coloured crusted erosions (“school sores”). Impetigo is most common in children (especially boys), but may also affect adults if they have low immunity to the bacteria. It is prevalent worldwide. Peak onset is during summer. The following factors predispose to impetigo. Group A streptococcal infection may rarely lead to acute post-streptococcal glomerulonephritis 3–6 weeks after the skin infection. The following steps are used to treat impetigo. Cleanse the wound; use moist soaks to gently remove crusts. Apply antiseptic or antibiotic ointment. If impetigo is extensive, oral antibiotics are recommended. Wash daily with antibacterial soap or soak in a bleach bath. Avoid close contact with others. Children must stay away from school until crusts have dried out. Use separate towels and flannels. Change and launder clothes and linen daily.
Cellulitis is a common bacterial infection of the skin, which can affect all ages. It usually affects a limb but can occur anywhere on the body. Symptoms and signs are usually localised to the affected area but patients can become generally unwell with fevers, chills and shakes (sepsis or bacteraemia). Severe or rapidly progressive cellulitis may lead to septicaemia (blood poisoning), necrotising fasciitis (a more serious soft tissue infection), or endocarditis (heart valve infection). Cellulitis is more common in some situations. The following lists those who may be at greater risk of developing cellulitis: Previous episode(s) of cellulitis, venous disease (eg gravitational eczema, leg ulceration) and/or lymphoedema, injury, diabetes, alcoholism, obesity, tinea pedis (or athlete's foot) in the toes of the affected limb. Although many people attribute an episode of cellulitis to an unseen spider bite, they are falsely blamed.
Cellulitis is potentially serious and should be assessed by a medical practitioner promptly. The management of cellulitis is becoming more complicated due to rising rates resistant bacteria. Most patients can be treated with oral antibiotics at home, usually for 5 to 10 days. However if there are signs of systemic illness or extensive cellulitis, treatment may require intravenous antibiotics either as an outpatient or in hospital. Treatment for uncomplicated cellulitis is usually for 10 to 14 days but antibiotics should be continued until all signs of infection have cleared (redness, pain and swelling) – sometimes for several months.