Impetigo - Bacterial Infections: Pyodermas

Bacterial Infections: Pyodermas

Also called pyodermas, pus-forming bacterial infections of the skin may be primary or secondary. Primary skin infections orig-inate in previously normal-appearing skin and are usually caused by a single organism. Secondary skin infections arise from a pre-existing skin disorder or from disruption of the skin integrity from injury or surgery. In either case, several microorganisms may be implicated (eg, Staphylococcus aureus, group A strepto-cocci). The most common primary bacterial skin infections are impetigo and folliculitis. Folliculitis may lead to furuncles or car-buncles.

IMPETIGO

Impetigo is a superficial infection of the skin caused by staphylo-cocci, streptococci, or multiple bacteria. Bullous impetigo, a more deep-seated infection of the skin caused by S. aureus, is character-ized by the formation of bullae (ie, large, fluid-filled blisters) from original vesicles. The bullae rupture, leaving raw, red areas.

The exposed areas of the body, face, hands, neck, and ex-tremities are most frequently involved. Impetigo is contagious and may spread to other parts of the patient’s skin or to other members of the family who touch the patient or use towels or combs that are soiled with the exudate of the lesions.

Although impetigo is seen at all ages, it is particularly common among children living in poor hygienic conditions. It often fol-lows pediculosis capitis (head lice), scabies (itch mites), herpes simplex, insect bites, poison ivy, or eczema. Chronic health prob-lems, poor hygiene, and malnutrition may predispose an adult to impetigo. Some people have been identified as asymptomatic car-riers of S. aureus, usually in the nasal passages.

Clinical Manifestations

The lesions begin as small, red macules, which quickly become discrete, thin-walled vesicles that soon rupture and become covered with a loosely adherent honey-yellow crust (Fig. 56-1). These crusts are easily removed to reveal smooth, red, moist surfaces on which new crusts soon develop. If the scalp is in-volved, the hair is matted, which distinguishes the condition from ringworm.

Medical Management

Systemic antibiotic therapy is the usual treatment. It reduces con-tagious spread, treats deep infection, and prevents acute glomeru-lonephritis (ie, kidney infection), which may occur as an aftermath of streptococcal skin diseases. In nonbullous impetigo, benzathine penicillin or oral penicillin may be prescribed. Bullous impetigo is treated with a penicillinase-resistant penicillin (eg, cloxacillin, dicloxacillin). In penicillin-allergic patients, erythromycin is an effective alternative.

Topical antibacterial therapy (eg, mupirocin) may be pre-scribed when the disease is limited to a small area. However, top-ical therapy requires that the medication be applied to the lesions several times daily for a week. The treatment regimen may be im-possible for some patients or their caregivers to follow. Topical antibiotics generally are not as effective as systemic therapy in eradicating or preventing the spread of streptococci from the res-piratory tract, thereby increasing the risk for developing glomeru-lonephritis.

When topical therapy is prescribed, lesions are soaked or washed with soap solution to remove the central site of bacterial growth, giving the topical antibiotic an opportunity to reach the infected site. After the crusts are removed, a topical medication (eg, Polysporin, bacitracin) may be applied. Gloves are worn when providing patient care. An antiseptic solution, such as povidone-iodine (Betadine) may be used to clean the skin, reduce bacterial content in the infected area, and prevent spread.

Nursing Management

The nurse instructs the patient and family members to bathe at least once daily with bactericidal soap. Cleanliness and good hy-giene practices help prevent the spread of the lesions from one skin area to another and from one person to another. Each per-son should have a separate towel and washcloth. Because im-petigo is a contagious disorder, infected people should avoid contact with other people until the lesions heal.