Cellulitis and erysipelas

CLINICAL MANIFESTATIONS:areas of skin erythema, edema, and warmth. erysipelas involves the upper dermis and superficial lymphatics, whereas cellulitis involves the deeper dermis and subcutaneous fat.erysipelas has more distinctive anatomic features than cellulitis; erysipelas lesions are raised above the level of surrounding skin, and there is a clear line of demarcation. Involvement of the ear (Milian's ear sign) is a distinguishing feature for erysipelas, since this region does not contain deeper dermis tissue. erysipelas tend to have acute onset of symptoms with systemic manifestations including fever and chills; patients with cellulitis tend to have a more indolent course with development of localized symptoms over a few days' time. DIAGNOSIS:based upon clinical manifestations. Cultures of blood, needle aspirations, or punch biopsies are usually not useful in the setting of mild infection.Blood cultures are positive in less than 5 percent of cases. Cultures of blood, pus, or bullae are more useful and should be performed in patients with systemic toxicity, extensive skin involvement, underlying comorbidities (lymphedema, malignancy, neutropenia, immunodeficiency, splenectomy, diabetes), special exposures (animal bite, water-associated injury) or recurrent or persistent cellulitis. MICROBIOLOGY — The vast majority of cases of erysipelas are caused by beta-hemolytic streptococci. The most common cellulitis pathogens are beta-hemolytic streptococci (groups A, B, C, G, and F) and S. aureus, including methicillin-resistant strains (MRSA); gram-negative aerobic bacilli are identified in a minority of cases TREATMENT: Most patients develop mild cellulitis and can be treated with oral antibiotics; patients with signs of systemic toxicity or erythema that has progressed rapidly should be treated initially with parenteral antibiotics. Attention to dosing is important, particularly in obese individuals. Treatment of cellulitis for neonates usually requires hospitalization and initial parenteral therapy, except for the mildest of cases. Empiric therapy must include coverage for group B streptococcus in addition to methicillin-resistant Staphylococcus aureus and other beta-hemolytic streptococci. Empiric parenteral therapy options include vancomycin plus either cefotaxime or gentamicin. Antibiotics that should be avoided in this age group include tetracyclines, trimethoprim-sulfamethoxazole, and ceftriaxone (cefotaxime is preferred over ceftriaxone). Dosing is weight- and age-based (table 1). Therapy is usually administered for 7 to 10 days. Patients with purulent cellulitis (eg, cellulitis associated with purulent drainage or exudate, in the absence of a drainable abscess) should be managed with empiric therapy for infection due to MRSA, pending culture results. Options for empiric oral therapy for treatment of MRSA include (table 2): ■Clindamycin ■Trimethoprim-sulfamethoxazole ■Tetracycline (doxycycline or minocycline) ■Linezolid or tedizolid Patients with nonpurulent cellulitis (eg, cellulitis with no purulent drainage or exudate and no associated abscess) should be managed with empiric therapy for infection due to beta-hemolytic streptococci and MSSA. Empiric antimicrobial therapy for nonpurulent cellulitis (including beta-hemolytic streptococci and MSSA but not MRSA) Adults Children age >28 days Oral therapy Dicloxacillin 500 mg orally every six hours 25 to 50 mg/kg per day orally in four doses Cephalexin* 500 mg orally every six hours 25 to 50 mg/kg per day orally in three or four doses Clindamycin• 300 to 450 mg orally every six to eight hours 20 to 30 mg/kg per day orally in four doses Intravenous therapy Cefazolin* 1 to 2 grams intravenously every eight hours 100 mg/kg per day intravenously in three or four doses Oxacillin 2 grams intravenously every four hours 150 to 200 mg/kg per day intravenously in four or six doses Nafcillin 2 grams intravenously every four hours 150 to 200 mg/kg per day intravenously in four or six doses Clindamycin• 600 to 900 mg intravenously every eight hours 25 to 40 mg/kg per day intravenously in three or four doses Follow-up — Patients with cellulitis typically report symptomatic improvement within 24 to 48 hours of beginning antimicrobial therapy, although visible improvement of clinical manifestations may take up to 72 hours. Continuing extension of erythema or worsening systemic symptoms after this period of time should prompt consideration of resistant pathogens or alternative diagnoses. RECURRENT CELLULITIS — Management of recurrent infection can be a challenging problem. In a study of 209 cases of cellulitis, recurrences were observed in 17 percent of patients. The efficacy of prophylactic antibiotics for management of recurrent cellulitis is unclear, especially in patients with obesity(BMI>33), multiple episodes or lymphedema in lower extremities. For known or presumed beta-hemolytic streptococcal infection, options for prophylactic antibiotics include monthly or bimonthly intramuscular benzathine penicillin injections (1.2 million units for patients who weigh >27 kg; 600,000 units for patients who weigh ≤27 kg) or oral therapy with penicillin V (250 to 500 mg orally twice daily). Staphylococcal infection prophylaxis may be attempted with clindamycin (150 mg orally once daily for adults) [66]. Staphylococcal prophylaxis for recurrent cellulitis is rarely necessary in children. Suppressive therapy may be continued for several months with interval assessment for relapse. Alternatively, patients may self-initiate antibiotic therapy immediately when symptoms of infection begin and seek medical attention. SUMMARY AND RECOMMENDATIONS ■Cellulitis and erysipelas manifest as areas of skin erythema, edema, and warmth in the absence of underlying suppurative foci. Erysipelas has more distinctive anatomic features than cellulitis; erysipelas lesions are raised above the level of surrounding skin so that a clear line of demarcation between involved and uninvolved tissue is usually present. (See 'Clinical manifestations' above.) ■Predisposing factors include disruption to the skin barrier as a result of trauma (such as penetrating wounds or injection drug use), inflammation (such as eczema or radiation therapy), preexisting skin infection (such as impetigo or tinea pedis), and edema (due to venous insufficiency). (See 'Clinical manifestations' above.) ■The diagnosis of cellulitis is based upon clinical manifestations. Cultures are necessary only in patients with systemic toxicity, extensive skin involvement, underlying comorbidities, special exposures (animal bite, water-associated injury), or recurrent or persistent cellulitis. (See 'Diagnosis' above.) ■The most common causes of cellulitis are beta-hemolytic streptococcus (groups A, B, C, G, and F), and other pathogens include Staphylococcus aureus; gram-negative aerobic bacilli are identified in a minority of cases. Beta-hemolytic streptococci are the predominant cause of erysipelas. (See 'Microbiology' above.) ■Management of cellulitis and erysipelas should include supportive measures, such as elevation of the affected area and treatment of underlying predisposing conditions. (See 'Nonantibiotic therapy' above.) ■Most patients develop mild cellulitis and can be treated with oral antibiotics. We recommend that patients with signs of systemic toxicity or erythema that has progressed rapidly should be treated initially with parenteral antibiotics (Grade 1B). Initial parenteral antibiotics are also indicated for most neonates with cellulitis (table 1). (See 'Cellulitis' above.) ■Patients with nonpurulent cellulitis should be managed with empiric therapy for infection due to beta-hemolytic streptococci and methicillin-susceptible S. aureus (MSSA) (table 4). Patients with nonpurulent cellulitis and additional risk factors for MRSA (table 5) should be managed with empiric therapy for infection due to beta-hemolytic streptococci and methicillin-resistant S. aureus (MRSA) (table 6). (See 'Nonpurulent' above.) ■Patients with purulent cellulitis (eg, cellulitis associated with purulent drainage or exudate, in the absence of a drainable abscess) should be managed with empiric therapy for infection due to MRSA, pending culture results (table 2) . (See 'Purulent' above.) ■Patients with classic manifestations of erysipelas and systemic manifestations, such as fever and chills, should be treated with parenteral therapy. Patients with mild infection or those who have improved following initial treatment with parenteral antibiotic therapy may be treated with oral therapy (table 7). (See 'Erysipelas' above.) ■The duration of therapy should be individualized depending on clinical response; 5 to 10 days is usually appropriate; longer duration of therapy may be warranted in patients with severe disease. (See 'Follow-up' above.) ■We suggest administration of suppressive antibiotic therapy for patients with recurrent cellulitis who have predisposing factors that cannot be alleviated (Grade 2B). (See 'Recurrent cellulitis' above.)