Dermatology

Staphylococcal Infections

Are You Confident of the Diagnosis?

Staphylococcal infections of the skin are most commonly caused by the organism Staphylococcus aureus. Staphylococcus epidermidis causes a smaller number of infections in this category. Skin infections are one of the most common manifestations of staphylococcal infections. The most common manifestations include folliculitis, furunculosis, impetigo, cellulitis, and abscesses. With the emergence of methicillin-resistant Staphylococcus aureus (MRSA), health-care providers must now consider this organism as the possible cause when a skin abscess is encountered.

  • Characteristic findings on physical examination

Physical findings are varied and include erythema, edema, and warmth of the skin, in the case of cutaneous abscesses; follicular papules and pustules in the setting of furunculosis and folliculitis, respectively; and honey-colored crusts, with or without bullae, in impetigo.

Who is at Risk for Developing this Disease?

Staphylococcal infections can develop in any individual. Individuals with diabetes, trauma, indwelling foreign bodies, and a history of intravenous drug abuse, are at increased risk. In addition, immunosuppression increases the risk for these infections. Individuals with the following conditions are at greater risk: chronic steroid therapy, chemotherapy, malignancies, dialysis for kidney failure, AIDS, sickle cell disease, peripheral vascular disease, inflammatory bowel disease, and severe burns.

What is the Cause of the Disease?

  • Etiology

  • Pathophysiology

S. aureus is a gram-positive organism which is both coagulase- and catalse-positive. The organisms provide a number of toxins (Table I), which are responsible for the clinical manifestations of disease.

Table I.

Etiology and pathophysiology of staphylococcal infections
Cytotoxin Gene Mechanism of action Cutaneous manifestation
Panton-Valentine leukocidin lukS-PV, lukF-PV dermonecrosis, leukocytoclasis abscess, cellulitis, furuncles
lukE-lukD lukE, lukD dermonecrosis impetigo
a-hemolysin hla lysis of red blood cells, lymphocytes, and keratinocytes undefined

Systemic Implications and Complications

Most staphylococcal infections of the skin are limited to the skin. In rare instances, the infections can have complications, leading to morbidity and mortality. These complications include sepsis, endocarditis, toxic shock syndrome, Staphylococcal scalded skin syndrome, and the development of deeper infections such as necrotizing fasciitis.

Treatment Options

Treatment options are summarized in Table II.

Table II.

Treatment options for staphylococcal infections
Topical Systemic Surgical Adjunctive
Mupurocin ointment Anti-staphylococcal antibiotics Incision and drainage Decolonization with mupurocin ointment
Clindamycin Hibiclens cleanser
Tetracyclines Bleach baths
Trimethorprim-sulfamethoxasole
Intravenous antibiotics (clindamycin, oxacillin, vancomycin)

Optimal Therapeutic Approach for this Disease

The optimal treatment approach is outlined in the Algorithm 1.

Algorithm 1:

SSTI: Skin and soft tissue infection

Patient Management

Patients should be followed for recurrent disease as a sign that they may be persistently colonized with Staphylococci. Repeated decolonization or referral to an infection disease specialist should be considered. Decolonization of family members may be required. This can be accomplished through the use of antiseptic agents or bleach baths.

Unusual Clinical Scenarios to Consider in Patient Management

Patients who are immunocompromised or have other comorbidities should be followed closely. If a patient has a worsening infection, fever, and chills, immediate follow-up should be arranged, to rule out the development of cellulitis or systemic spread.

What is the Evidence?

Graham, PL, Lin, SX, Larson, EL.. "A US population-based survey of Staphylococcus aureus colonization". Ann Intern Med. vol. 144. 2006. pp. 318-25.

(The prevalence of colonization with S aureus and with MRSA was 31.6% and 0.84%, respectively, in the noninstitutionalized US population. People younger than 65 years of age, men, persons with less education, and persons with asthma were more likely to acquire S aureus.)

Liu, C, Bayer, A, Cosgrove, SE, Daum, RS, Fridkin, SK, Gorwitz, RJ, Kaplan, SL. "Clinical practice guidelines by the Infectious Diseases Society of America for the treatment of Methicillin-Resistant Staphylococcus Aureus infections in adults and children". Clin Infect Dis.. vol. 52. 2011 Feb 1. pp. e18-55.

(These are current evidence-based guidelines for the management of patients with methicillin-resistant Staphylococcus aureus (MRSA) infections.)

Kil, EH, Heymann, WR, Weinberg, JM.. "Methicillin-resistant Staphylococcus aureus: an update for the dermatologist, Part 2: Pathogenesis and cutaneous manifestations". Cutis. vol. 81. 2008. pp. 247-54.

(A review of the manifestations of MRSA.)
You must be a registered member of Endocrinology Advisor to post a comment.

Sign Up for Free e-Newsletters

CME Focus