Researchers Study the Health and Economic Impacts of Cellulitis Misdiagnosis

Bringing down the rate of infections misdiagnosed as bacterial is taking increasing precedence in hospitals throughout the United States, and now, a new study shows how the rate and impact of cellulitis misdiagnosis affects the healthcare system.

A relatively common, and sometimes serious, bacterial skin infection, cellulitis is caused when Streptococcus and Staphylococcus enter the skin through a break such as a cut, wound, or an area of irritated skin. These infections most commonly occur in the lower leg and foot, and individuals with a recent injury, a skin condition, a weakened immune system, or are partaking in intravenous drug use can be at greater risk for developing the skin condition. Cellulitis infections caused by the virulent superbug methicillin-resistant Staphylococcus aureus (MRSA) are one of the biggest threats among healthcare-associated infections, according to the Centers for Disease Control and Prevention (CDC). The most common symptoms of cellulitis and MRSA cellulitis are red, swollen, tender, or painful skin wounds that are warm to the touch and blister.

Researchers from Massachusetts General Hospital, Brigham and Women’s Hospital in Boston, and the Tulane School of Public Health and Tropical Medicine in New Orleans recently studied the national healthcare burden of misdiagnosed lower extremity cellulitis. Their findings were recently published in the journal JAMA Dermatology. The study analyzed the cumulative costs and consequences that come when emergency room doctors misdiagnose skin infections as cellulitis, an issue they noted as common and holding negative implications when it comes to public health. Cellulitis results in 2.3 million emergency room visits in the United States each year, and these infections account for 10% of all hospitalizations related to infectious disease. Outpatient care—including diagnosis, observation, and treatment–for cellulitis totaled $3.7 billion in 2006. A physical examination and medical history are typically used to diagnose cellulitis, rather than blood or skin culture diagnostics, the study authors noted. As such, a misdiagnosis of cellulitis can occur in cases of other pseudocellulitis conditions which mimic cellulitis, such as dermatitis, lymphedema, and deep venous thrombosis.

The researchers conducted a retrospective cross-sectional study of emergency room patients in a large urban hospital admitted and diagnosed with lower extremity cellulitis. The cases occurred from June 2010 to December 2012 with a total of 259 patients. The authors found that of those patients, 79 (30.5%) received a misdiagnosis of cellulitis. Of those who were misdiagnosed, 52 were admitted to the hospital due to their diagnosis. However, the research team found that 44 (84.6%) patients were unnecessarily hospitalized and 48 (92.3%) received unneeded antibiotics. With their data, the study team concluded that cellulitis misdiagnosis in the United States leads to 50,000 to 130,000 excess hospitalizations and an additional $195 million to $515 million in healthcare costs that could have been avoided. Some 44,000 patients with pseudocellulitis receive unnecessary antibiotics each year, leading to hospital readmissions and complications from these medications. “Antibiotic exposure and unnecessary hospitalization places patients at risk for C. difficile infection, anaphylaxis, gastrointestinal distress, dermatological complications, and nosocomial infections,” noted the authors in the study. “Our study highlights potentially avoidable complications and opportunities to reduce significant morbidity and mortality from cellulitis misdiagnosis."

“Although the majority of cellulitis is diagnosed and treated by general physicians, dermatologists have a special expertise in differentiating cellulitis from its mimics,” study author, Arash Mostaghimi, MD, MPA, MPH, told Contagion. “There’s data that early dermatology diagnosis leads to reduction of misdiagnosis and incorrect treatment with antibiotics in patients with presumed cellulitis in a variety of settings. The challenge is that dermatologists are a scarce resource, and it’s not reasonable to have dermatologists see every single patient thought to have this common problem.”

The findings follow earlier reports showing a high rate of unnecessary prescribing and overuse of antibiotics for infections that are not bacterial in the US healthcare system. The CDC, in partnership with the Pew Charitable Trusts, supports the White House’s National Action Plan for Combating Antibiotic Resistant Bacteria, which calls for improved antibiotic stewardship and a 50% reduction in unnecessary antibiotic use by 2020. “Misdiagnosis of cellulitis has considerable implications for antibiotic stewardship,” according to the authors of the new study. “Nearly a third of pseudocellulitis patients in our study experienced a complication as a direct result of unnecessary treatment for presumed cellulitis. Antibiotic use is associated with increased risk of antibiotic drug toxic effects, anaphylaxis, prolonged hospitalization, and selection of resistant microorganisms.”

With additional education for providers who do not specialize in dermatology, the authors noted, emergency rooms could bring down the rate of cellulitis misdiagnoses and unneeded antibiotic prescriptions. “Hopefully, over time we’ll develop more advanced molecular tests to give us quantitative data that we can use to differentiate cellulitis from non-infectious entities,” Dr. Mostaghimi said.