Misdiagnosis of Uncomplicated Cellulitis: a Systematic Review and Meta-analysis

BACKGROUND

Cellulitis is a clinical diagnosis with several mimics and no gold standard diagnostic criteria. Misdiagnosis is common. This review aims to quantify the proportion of cellulitis misdiagnosis in primary or unscheduled care settings based on a second clinical assessment and describe the proportion and types of alternative diagnoses.

METHODS

Electronic searches of Medline, Embase and Cochrane library (including CENTRAL) using MeSH and other subject terms identified 887 randomised and non-randomised clinical trials, and cohort studies. Included articles assessed the proportion of cellulitis misdiagnosis in primary or unscheduled care settings through a second clinical assessment up to 14 days post initial diagnosis of uncomplicated cellulitis. Studies on infants and patients with (peri-)orbital, purulent and severe or complex cellulitis were excluded. Screening and data extraction was conducted independently in pairs. Risk of bias was assessed using a modified risk of bias tool from Hoy et al. Meta-analyses were undertaken where ≥ 3 studies reported the same outcome.

RESULTS

Nine studies conducted in the USA, UK and Canada, including a total of 1600 participants, were eligible for inclusion. Six studies were conducted in the inpatient setting; three were in outpatient clinics. All nine included studies provided estimates of the proportion cellulitis misdiagnosis, with a range from 19 to 83%. The mean proportion misdiagnosed was 41% (95% CI 28 to 56% for random effects model). Heterogeneity between studies was very high both statistically (I2 96%, p-value for heterogeneity < 0.001) and clinically. Of the misdiagnoses, 54% were attributed to three conditions (stasis dermatitis, eczematous dermatitis and edema/lymphedema).

DISCUSSION

The proportion of cellulitis misdiagnosis when reviewed within 14 days was substantial though highly variable, with the majority attributable to three diagnoses. This highlights the need for timely clinical reassessment and system initiatives to improve diagnostic accuracy of cellulitis and its most common mimics.

TRIAL REGISTRATION

Open Science Framework ( https://osf.io/9zt72 ).

Confusion With Presentations of Calcium Pyrophosphate Dihydrate Disease: A Report of Two Cases Mistaken for Cellulitis

Both pseudogout and cellulitis are diseases that may mimic one another in clinical practice. We discuss two cases of acute calcium pyrophosphate dihydrate (CPPD) arthritis mistaken for cellulitis in the emergency department. Both patients experienced significant improvement after management was changed to treat CPPD. These cases highlight how it is essential for physicians to consider CPPD as a differential diagnosis for a patient that is presenting with signs of inflammation in any joint.

Distinguishing clinical features for pseudocellulitis in pediatric inpatients: A retrospective study

The clinical features of 588 pediatric inpatients admitted with a diagnosis of cellulitis were reviewed with attention to diagnostic accuracy of true cellulitis (95.1%) versus pseudocellulitis (4.9%) and utilization of specialist consultations (28.1% infectious disease, 6.1% dermatology). Laboratory abnormalities were unable to distinguish cellulitis from pseudocellulitis, supporting previous studies that routine laboratory evaluation may be unnecessary for this diagnosis. Higher rates of pseudocellulitis were identified in cases involving specialist consultation by both dermatology (44.8% pseudocellulitis, 4.1% true cellulitis, p < .001) and infectious disease (48.3% pseudocellulitis, 27.0% true cellulitis, p = .01). Thus, consultation may improve the diagnostic accuracy of suspected cellulitis among pediatric inpatients.

Comparing skin surface temperature to clinical documentation of skin warmth in emergency department patients diagnosed with cellulitis

Objective

To compare clinical documentation of skin warmth to patient report and quantitative skin surface temperatures of patients diagnosed with cellulitis in the emergency department (ED).

Methods

Adult patients (≥18 years) presenting to the ED with an acute complaint involving visible erythema of the lower extremity were prospectively enrolled. Those diagnosed with cellulitis were included in this analysis. Participant report of skin warmth was recorded and skin surface temperature values were obtained from the affected and corresponding unaffected area of skin using thermal cameras. Average temperature (Tavg) was extracted from each image and the difference in Tavg between the affected and unaffected limb was calculated (Tgradient). Clinical documentation of skin warmth was compared to patient report and measured skin warmth (Tgradient >0°C).

Results

Among 126 participants diagnosed with cellulitis, 110 (87%) exhibited objective warmth (Tgradient >0°C) and 58 (53%) of these cases had warmth documented in the physical examination. Of those with objective warmth, 86 (78%) self-reported warmth and 7 (6%) had warmth documented in their history of present illness (HPI) (difference = 72%, 95% confidence interval [CI]: 62%-82%; P < 0.001). A significant difference was observed for Tavg affected when warmth was documented (32.1°C) versus not documented (31.0°C) in the physical examination (difference = 1.1°C, 95% CI: 0.29-1.94; P = 0.0083). No association was found between Tgradient and patient-reported or HPI-documented warmth.

Conclusions

The majority of ED-diagnosed cellulitis exhibited objective warmth, yet significant discordance was observed between patient-reported, clinician-documented, and measured warmth. This raises concerns over inadequate documentation practices and/or the poor sensitivity of touch as a reliable means to assess skin surface temperature. Introduction of objective temperature measurement tools could reduce subjectivity in the assessment of warmth in patients with suspected cellulitis.

Acute inflammatory edema as a variant of pseudocellulitis resolved after transcatheter aortic valve implantation

Acute inflammatory edema is a noninfectious inflammatory condition of the skin that is commonly seen in critically ill patients. It is characterized by edematous, erythematous, and nontender plaques involving the abdomen and thighs, sparing areas of the skin subject to pressure. Risk factors include fluid overload, hypoalbuminemia, and obesity. Differentiating acute inflammatory edema from cellulitis can be challenging. Supportive care is the mainstay therapy for acute inflammatory edema, with interventions primarily focused on lowering the fluid burden. We report an unusual case of a nonobese patient in the outpatient setting with acute inflammatory edema.

Acute Inflammatory Edema: A Case Report with Histopathological and Immunohistochemical Findings

Acute inflammatory edema (AIE) is a rare variant of pseudocellulitis characterized by blanchable, erythematous, and edematous plaques mainly on the thighs and abdomen and sparing areas of increased pressure. The condition occurs predominantly in critically ill patients with hypoalbuminemia, those with increased body mass index, and those with evidence of fluid overload. AIE was introduced in 2019; however, its histopathological picture has never been elucidated in the literature. We report a case of AIE in a 64-year-old Thai woman with several comorbidities and illustrate its histopathological and immunohistochemical features for the first time. Treatment with diuretics, fluid restriction, and adjuvant hemodialysis revealed marked improvement after ten days. Our report emphasizes that AIE is a distinct dermatosis with specific characteristics that help differentiate AIE from cellulitis and other pseudocellulitic conditions. Furthermore, our observations support the role of lymphatic alterations in the pathogenesis of the disease.

pseudocellulitis

Introduction: The immunologic mechanisms between cellulitis and pseudocellulitis differ greatly, even though their clinical presentations may overlap.Areas covered: This article discusses cellulitis and common entities within the pseudocellulitis spectrum including acute lymphedema, superficial venous thrombosis, allergic contact dermatitis, lipodermatosclerosis, stasis dermatitis, erythema nodosum, cutaneous gout, and bursitis. The literature search was conducted from PubMed search engine between March and May 2021.Expert commentary: While immunologic differences in cellulitis and the various entities of pseudocellulitis are clear, there is a practice gap in applying these differences to the clinic and hospital setting. Further, existing studies are weakened by the lack of a gold-standard diagnosis in this disease category. Additional work is necessary in developing a gold-standard for the diagnosis and secondly, to project these immunologic differences as biomarkers to differentiate sterile inflammation from a potential life threatening bacterial or fungal infection.

A case of exemestane induced pseudocellulitis

Exemestane is an aromatase inhibitor increasingly incorporated into the treatment of hormone sensitive breast cancer. Pseudocellulitis describes an uncomplicated inflammation of the dermis and hypodermis from a noninfectious etiology. It presents with erythema, swelling, warmth and tenderness of the affected skin. We report a case of a 47-year-old Indian woman who presented with 2-day history of redness and swelling of her left lower limb. There were no other symptoms. She was recently switched from tamoxifen to aromasin as adjuvant treatment for her breast cancer. Examination revealed erythema, edema, and warmth over the left lower limb. Laboratory investigations and doppler ultrasound scan were unremarkable. Skin punch biopsy showed dermal inflammatory infiltrate composed of lymphocytes, histiocytes and scattered eosinophils and neutrophils, concentrated in the superficial and deep perivascular regions suggestive of a leukocytoclastic vasculitis. The diagnosis of exemestane induced leukocytoclastic vasculitis presenting as pseudocellulitis was made. She was given a course of systemic and topical steroids with completere solution of lesion within 2 weeks. This is the first reported case of exemestane induced pseudocellulitis to our knowledge. Dermatologists and clinicians should be aware of this peculiar adverse drug reaction to avoid misdiagnosis and prevent unnecessary treatment.

Gemcitabine-induced pseudocellulitis: a case report and review of the literature

Gemcitabine is a chemotherapeutic agent used in a wide variety of solid tumours. Known side effects include a dose-limiting myelosuppressive toxicity, mild rash, and radiation-dependent dermatitis. Rarely, localized inflammation in the form of pseudocellulitis has also been observed. We present the case of a 77-year-old woman with a history of a Whipple procedure for pancreatic adenocarcinoma who presented to the emergency department after the start of gemcitabine therapy with increased erythema, swelling, and tenderness in her lower legs. Relevant past medical history included peripheral vascular disease, dyslipidemia, and hypertension. A diagnosis of gemcitabine-induced pseudocellulitis aggravated by venous stasis was confirmed after an extensive workup. This case report and the literature review describe this rare reaction, highlighting the need for increased recognition to avoid unnecessary therapeutic intervention.

A case of gemcitabine-related acute lipodermatosclerosis

INTRODUCTION

Gemcitabine is a chemotherapeutic agent used to treat several solid organ malignancies. The most common cutaneous toxicities are a mild erythematous rash and pruritus, which are often attributed to infectious etiologies. However, certain clinical characteristics may favor a drug-related reaction. Clinicians should recognize these phenomena to avoid potentially unnecessary antibiotic treatment or withdrawal of chemotherapeutic agents.

OBJECTIVE

We aim to report a case of gemcitabine-related acute lipodermatosclerosis-like eruption, add to the evolving classification of this condition, and highlight developing literature on gemcitabine that may explain this toxicity.

CASE

Dermatology was consulted for presumed cellulitis in a 62-year-old female with pancreatic carcinoma. The patient presented to the emergency department five days after her first dose of gemcitabine with erythema in both lower extremities. A diagnosis of gemcitabine-related acute lipodermatosclerosis was made and the patient was started on topical triamcinolone.

CONCLUSION

It is important to recognize gemcitabine-related acute lipodermatosclerosis in order to avoid unnecessary antibiotic use and disruptions in chemotherapy.

Mass Compression from Recurrent Lymphoma Mimicking Lower Extremity Cellulitis

Cellulitis is a common skin and soft tissue infection with substantial misdiagnosis rates due to its nonspecific clinical characteristics. In this report, we present a patient with recurrent metastatic diffuse large B-cell lymphoma (DLBCL) masquerading as a unilateral lower extremity cellulitis. A 62-year-old man with a history of DLBCL, in remission for two years, presented with a two-week history of swelling and erythema of the right thigh and leg. Despite treatment with clindamycin and cephalexin, the redness and swelling continued to progress. On presentation to the emergency department, vitals were within normal limits, laboratory workup was significant only for borderline anemia and thrombocytopenia, and bilateral lower extremity ultrasound was negative for a clot. The patient was evaluated by a dermatologist who recommended further imaging workup for proximal vascular compression given the uniformity of inflammation and edema in the absence of fever or systemic symptoms. Imaging revealed retroperitoneal lymphadenopathy, right pelvic side wall and right inguinal lymphadenopathy, an intramuscular lymphomatous involvement of the right iliopsoas muscle, and mass compression of the right external iliac vein. Bone marrow and soft-tissue biopsies confirmed recurrent and metastatic DLBCL. In this patient, the atypical cellulitis-like features are likely due to venous and lymphatic obstruction secondary to mass effect from metastasis. Going forward, clinicians should consider compression-induced edema as a sign of primary or recurrent malignancy in patients with refractory or atypical cellulitis.

Estimating the health care costs associated with recurrent cellulitis managed in the outpatient setting

BACKGROUND

Recurrent cellulitis is diagnosed in 22% to 49% of all cellulitis cases, but little is known about the costs associated with these cases.

OBJECTIVE

To characterize patients with recurrent cellulitis in the outpatient setting and estimate the associated costs.

METHODS

A retrospective chart review was conducted for adult patients who presented to the outpatient facilities at our institution from January 1, 2007, to December 31, 2011, with recurrent cellulitis. Data provided by the Centers for Medicare and Medicaid Services were used.

RESULTS

A total of 157 patients were identified; 56% were male, with a mean age of 62.7 years. The mean number of episodes of cellulitis per patient was 3. Antibiotics were prescribed for all patients with a diagnosis of recurrent cellulitis, with 93% treated with oral antibiotics and 17.6% treated with intravenous antibiotics. A total of 1081 laboratory and 175 radiologic imaging tests were ordered. The minimum average cost per cellulitis episode was $586.91; the average cost per visit was $292.50.

LIMITATIONS

Retrospective study; use of a single, large academic institution; and utilization of cost estimates that may not adequately reflect the variation of costs across closed-system sites or geographic regions. There was no accounting for the nonfinancial or opportunity costs associated with hospitalization, such as lost days of employment or child care and any long-term morbidities, among others.

CONCLUSIONS

Recurrent cellulitis in the outpatient setting costs about $586.91 per episode. Although there is no criterion standard for diagnosis or treatment of cellulitis, our analysis demonstrates the need for more evidence-based management to achieve better outcomes and reduce the significant health care costs.