Common Bacterial Infections of the Skin

By Mark H. Lupin, BSc, MD, FRCPC

Our skin is host to a number of bacteria, most of which are beneficial. Including the friendly flora in our gut, more than 200 species of bacteria reside within the tissues exposed to the external environment. Skin infections result from these bacteria when the integrity of the skin breaks down or when the immune defense system is weak.

Skin infections can occur on the skin surface or deeper within the skin tissue. The most common bacteria that infect the skin are Staphylococcus aureus and Streptococcus pyogenes. Read more about bacterial infections on bacterial infections

TYPES OF BACTERIAL INFECTIONS:

Impetigo and Ecthyma

Impetigo begins with a redness of the skin and progresses to blisters that fill with fluid and itch, and then produce honey-colored crusts. Lesions usually form around the nose and face. Ecthyma is a deeper version of impetigo that usually forms on the legs. It causes large boils, crusts, and deep sores that leave scars.

Folliculitis

Folliculitis is an infection of the hair follicles. It produces pimplelike skin bumps and small blisters with pus. Folliculitis occurs on the face, upper trunk, arms, and buttocks. When the infection goes deeper, feels tender, and produces more pus, it is furunculosis. Carbuncles are furuncles that have fused.

Abscess

An abscess is a deep infection that appears like a closed blister or an open hole with pus. It is usually tender and becomes sore and painful as the infection progresses.

Erysipelas and Cellulitis

Erysipelas is a superficial infection that tends to occur in young children and the elderly. It is also seen in those who have chronic swelling of the limbs, are addicted to alcohol, have diabetes mellitus, or have experienced trauma. Erysipelas mostly occurs on the face or legs. A fever occurs abruptly, the cheeks become red, and the skin feels hot, tense, and swollen. Cellulitis is a deeper form of this infection.

TREATMENTS:

Bacterial skin infections are treated according to their severity. Your physician may incise and drain deeper infections and abscesses, and recommend that you apply warm compresses. Creams such as Fucidin® or Bactroban® are prescribed for mild stages of:

• impetigo
• ecthyma
• folliculitis
• abscess

If the infection is more extensive, oral antibiotics such as Cloxacillin or Cephalexin are used as well as those in the erythromycin family. Penicillin is often used to treat for strep.

Antibiotic resistance is an increasing problem so it is best to have early adequate proper treatment to minimize risk of exposure to antibiotics and lower the risk of transmission to others.

During treatment, remember to wash your hands daily with an antibacterial solution such as Trisan®, Tersaseptic® or Hibitane®, or use a product like Safe4Hours® (www.invisicare.com) which kills bacteria for four hours. Hand washing is the most important thing you can do to minimize the spread of infection.

If you suspect a bacterial skin infection, see your doctor before it becomes severe. Due to the increase of bacterial resistance to drugs in general, it is important to take the full course of your prescribed medicines.

About the author:

Dr. Mark Lupin, based in Victoria, British Columbia, is an instructor at the Department of Dermatology, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia. He has a special interest in cosmetic and laser procedures. www.Cosmedica.ca.