dermatologic disorders
Cellulitis
Treatment of Cellulitis
Antibiotics Antibiotics are the treatment of choice, and selection is based on the presence or absence of purulence and other risk factors for serious and/or resistant infection ( Treatment reference ). Treatments are usually not given for a fixed interval but are continued until there is satisfactory clinical response—but typically for not less than 1 week. Immobilization and elevation of the affected area help reduce edema; cool, wet dressings relieve local discomfort. Compression therapy can help prevent repeat episodes of leg cellulitis in patients with recurrent cellulitis who have chronic lower extremity edema. For most patients with nonpurulent cellulitis, empiric therapy effective against both group A streptococci andS. aureusis used. Oral therapy is usually adequate for mild infections, typically withdicloxacillin250 mg orcephalexin500 mg 4 times a day. In patients allergic to penicillin,clindamycin300 to 450 mg 3 times a day is an alternative. Patients with mild cellulitis caused by mammalian bites can be treated as outpatients withamoxicillin/clavulanic acid875/125 mg orally every 12 hours. In patients allergic to penicillin,clindamycin300 to 450 mg 3 times a day plus either an oral fluoroquinolone (eg,ciprofloxacin500 mg every 12 hours) or double-strength sulfamethoxazole/trimethoprim(800 mg sulfamethoxazole/160 mgtrimethoprim) orally 2 times a day may be used. Cellulitis that develops after exposure to fresh or brackish water should be treated with a 1st-generation cephalosporin such ascephalexin500 mg orally 4 times a day orcefazolin1 g IV every 8 hours in addition to a fluoroquinolone. If cellulitis develops after exposure to brackish or salt water,doxycycline100 mg orally 2 times a day should also be added. Likely infecting organisms tend to be similar in brackish and fresh water (eg,Vibriospecies,Aeromonasspecies,Shewanellaspecies,Erysipelothrix rhusiopathiae,Mycobacterium marinum,Streptococcus iniae). Cellulitis can recur in patients with risk factors such as tinea pedis, obesity, venous insufficiency, edema, and atopic dermatitis. These disorders should be identified and treated to decrease the likelihood of recurrent cellulitis. Prophylactic antibiotics such as benzathine penicillin 1.2 million units IM monthly orpenicillin Vorerythromycin250 mg orally 2 times a day for 1 to 12 months may be considered for patients who have 3 to 4 episodes of cellulitis per year despite treatment of risk factors. Patients taking prophylactic antibiotics should be assessed regularly to monitor for adverse effects and efficacy of treatment. Antibiotics should be continued until risk factors also have been managed. If these regimens prove unsuccessful, tissue culture may be required. Purulent cellulitisand other risk factors predispose to complicated (serious, eg, deeper, invasive, systemic) infection. Affected patients should receive coverage for MRSA. Risk factors for MRSA and complicated infection include the following: Penetrating trauma Surgical wounds Recent hospitalization or nursing home exposure Illicit IV drug use Proximity of infection to an implanted medical device such as a prosthetic joint Previous MRSA infection Known nasal colonization with MRSA Clinical features suggestive of serious infection Clinical features suggestive of MRSA or complicated infection (high-risk symptoms) include the following: Pain disproportionate to physical findings Cutaneous hemorrhage Bullae Skin sloughing Skin anesthesia Rapid progression Tissue gas Signs of systemic toxicity (fever or hypothermia, tachycardia, hypotension, delirium) For suspected MRSA without features suggesting complicated infection, empiric outpatient treatment is reasonable using double-strength sulfamethoxazole/trimethoprim(800 mg sulfamethoxazole/160 mgtrimethoprim) orally 2 times a day,doxycycline100 mg orally 2 times a day,linezolid600 mg orally 2 times a day, orclindamycin300 to 450 mg orally 3 times a day (however, resistance toclindamycinis becoming more prevalent). Patients who have more serious infections, with high-risk symptoms with suspected or confirmed MRSA, or whose oral therapy failed are hospitalized and typically are given one of the following: 15 mg/kg IV every 12 hours (drug of choice; see Antibiotic resistance ) Linezolid600 mg IV every 12 hours for 10 to 14 days, usually for highly resistant MRSA Daptomycin4 to 6 mg/kg IV once/day Teicoplanin 6 mg/kg IV every 12 hours for 2 doses, followed by 3 or 6 mg/kg IV or IM once a day to achieve targeted trough concentration (mechanism of action similar to that ofvancomycin; commonly used outside the United States to treat MRSA) The use of alternative medications for severe acute bacterial skin and skin structure infection (ABSSSI) withS. aureus(including MRSA) are based on availability, ease of administration, adverse effect profile, and cost. Alternatives include: Linezolidortedizolid(IV or oral) Delafloxacin(IV or oral) Omadacycline(IV or oral) Ceftarolineand ceftobiprole (which is only available in Canada and Europe) (IV) Dalbavancin,oritavancin, andtelavancin(IV) Cellulitis in a patient with neutropenia requires broad-spectrum antibiotic coverage.Vancomycinpluscefepimeormeropenemis recommended until blood culture results are available to guide therapy. Tissue culture should be strongly considered for identification of the causative organism because of the increased risk of fungal infection. Culture should be considered for patients who are immunocompromised if they are not responding to empiric therapy or if blood cultures do not isolate an organism and for patients with cellulitis at the site of certain injuries (eg, animal bite wounds, penetrating injuries). 1.Brindle R, Williams OM, Barton E, Featherstone P: Assessment of antibiotic treatment of cellulitis and erysipelas: A systematic review and meta-analysis.JAMA Dermatol155(9):1033–1040, 2019. doi: 10.1001/jamadermatol.2019.0884 