What diagnostic strategies can help differentiate cellulitis from other causes of red legs in primary care?

Bullous skin signs and laboratory surgical indicators can quickly and effectively differentiate necrotizing fasciitis from cellulitis

OBJECTIVES

The purpose of this prospective study was to investigate the different microorganisms associated with mortality, to evaluate the bullous skin sign, and to identify the positive predictive factors for differentiating necrotizing fasciitis (NF) from cellulitis on initial onset at the emergency department.

METHODS

This prospective study was conducted in 145 consecutive patients with NF and 159 patients with cellulitis. Age, sex, comorbidities, infection site, microbiological results, condition of skin lesions, laboratory findings, vital signs, and clinical outcomes were compared between the two groups at the time of admission to the emergency room.

RESULTS

A total of 15 patients in the NF group and two patients in the cellulitis group died, resulting in a mortality rate of 10.3% and 1.3%, respectively. The NF group had a significantly higher incidence of white blood cell counts, band form neutrophil, and C-reactive protein than the patients in the cellulitis group. Hemorrhagic bullae presentation appeared to have significantly associated with NF and death.

CONCLUSION

The following diagnostic indicators can be effectively used to differentiate NF from cellulitis at the initial onset: presence of hemorrhagic bullae, white blood cell counts >11,000 cells/mm³, band forms >0%, C-reactive protein >100 mg/l, and systolic blood pressure ≤90 mm Hg at the time of consultation.

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.

Red legs: how to differentiate between cellulitis, venous eczema and lipodermatosclerosis

Community nurses often encounter people with red legs. There are a number of reasons why an individual may develop red legs. The most common causes of red legs are cellulitis, venous eczema and lipodermatosclerosis. All have different causes and require different treatments. This article aims to enable readers to differentiate between these conditions which can appear similar, and to offer effective evidence-based care.

The Red Legs RATED tool to improve diagnosis of lower limb cellulitis in the emergency department

BACKGROUND

Lower limb cellulitis poses a significant burden for the Irish healthcare system. Accurate diagnosis is difficult, with a lack of validated evidence-based tools and treatment guidelines, and difficulties distinguishing cellulitis from its imitators. It has been suggested that around 30% of suspected lower limb cellulitis is misdiagnosed. An audit of 132 patients between May 2017 and May 2018 identified a pattern of misdiagnosis in approximately 34% of this cohort.

OBJECTIVE

The aim of this pilot project was to develop a streamlined service for those presenting to the emergency department with red legs/suspected cellulitis, through introduction of the 'Red Leg RATED' tool for clinicians.

METHOD

The tool was developed and introduced to emergency department clinicians. Individuals (n=24) presenting with suspected cellulitis over 4 weeks in 2018 were invited to participate in data gathering. Finally, clinician questionnaire feedback regarding the tool was evaluated.

RESULTS

Fourteen participants consented, 6 female and 8 male with mean age of 65 years. The tool identified 50% (n=7) as having cellulitis, of those 57% (n=4) required admission, 43% (n=3) were discharged. The remainder who did not have cellulitis (n=7) were discharged. Before introduction of the tool, all would typically have been admitted to hospital for further assessment and management of suspected lower limb cellulitis. Overall, 72% (n=10) of patients who initially presented with suspected cellulitis were discharged, suggesting positive impact of the tool. Clinician feedback suggested all were satisfied with the tool and contents.

CONCLUSION

The Red Leg RATED tool is user friendly and impacts positively on diagnosis treatment and discharge. Further evaluation is warranted.

Handheld infrared thermometer to evaluate cellulitis: the HI-TEC study

OBJECTIVES

Differentiating cellulitis from pseudocellulitis is challenging, and misdiagnosis leads to unnecessary antimicrobial use and increased healthcare expenditure. Clinical diagnosis remains the criterion standard and may involve expert consultation. Our objective was to evaluate the usefulness of a handheld infrared thermometer to improve diagnostic certainty in cases of suspected cellulitis.

METHODS

We conducted a cross-sectional study from August 2018 to January 2020 at a tertiary-care hospital in Montreal, Canada. We enrolled adult patients with suspected limb cellulitis. Using the infrared thermometer, we compared the average temperature of the affected area with that of the contralateral limb, and we used Youden's method to determine the optimal temperature difference which best differentiated cellulitis from pseudocellulitis as determined by an independent and blinded infectious diseases specialist. We used bootstrapping to estimate 95% confidence intervals for the sensitivity, specificity, and area under the receiver operating curve.

RESULTS

Of 65 patients screened for enrolment, 52 patients were recruited (median age: 64 years, IQR 52-76); 39 of these were diagnosed with cellulitis and 13 were not. The mean temperature difference between affected and unaffected limbs was 2.6°C (95%CI 2.1-3.1°C) for patients with cellulitis and 0.4°C (95%CI -1.2°C to 2.1°C) for patients without (p < 0.001). An average temperature difference between limbs of 0.8°C or more was 95% sensitive (95%CI 74-100%) and 69% specific (95%CI 44-95%) for the diagnosis of cellulitis (c-statistic 0.82).

CONCLUSIONS

In this proof-of-concept single-centre study, a handheld infrared thermometer was a useful aid to differentiate cellulitis from pseudocellulitis.

Achilles tendon rupture: what you need to know

Heel pain and a history of a 'pop' or feeling 'something go' are the buzz phrases classically associated with Achilles tendon rupture. However, the diagnosis is often missed in clinical practice because of the assumption that this is a sporting injury suffered only by the young or middle-aged. In a sedentary older patient, the injury may be dismissed as an ankle sprain. If swelling is present but no injury is recalled then deep vein thrombosis is suspected, but Achilles rupture is not. The diagnosis of Achilles tendon rupture is clinical, based on history and examination. Radiological imaging (ultrasound scan) is useful to plan orthopaedic management and exclude concomitant deep vein thrombosis. In most cases, non-operative management with the ankle held plantar flexed in a boot is the current best practice.

An interview study to determine the experiences of cellulitis diagnosis amongst health care professionals in the UK

OBJECTIVES

To explore healthcare professionals (HCPs) experiences and challenges in diagnosing suspected lower limb cellulitis.

SETTING

UK nationwide.

PARTICIPANTS

20 qualified HCPs, who had a minimum of 2 years clinical experience as an HCP in the national health service and had managed a clinical case of suspected cellulitis of the lower limb in the UK. HCPs were recruited from departments of dermatology (including a specialist cellulitis clinic), general practice, tissue viability, lymphoedema services, general surgery, emergency care and acute medicine. Purposive sampling was employed to ensure that participants included consultant doctors, trainee doctors and nurses across the specialties listed above. Participants were recruited through national networks, HCPs who contributed to the cellulitis priority setting partnership, UK Dermatology Clinical Trials Network, snowball sampling where participants helped recruit other participants and personal networks of the authors.

PRIMARY AND SECONDARY OUTCOMES

Primary outcome was to describe the key clinical features which inform the diagnosis of lower limb cellulitis. Secondary outcome was to explore the difficulties in making a diagnosis of lower limb cellulitis.

RESULTS

The presentation of lower limb cellulitis changes as the episode runs its course. Therefore, different specialties see clinical features at varying stages of cellulitis. Clinical experience is essential to being confident in making a diagnosis, but even among experienced HCPs, there were differences in the clinical rationale of diagnosis. A group of core clinical features were suggested, many of which overlapped with alternative diagnoses. This emphasises how the diagnosis is challenging, with objective aids and a greater understanding of the mimics of cellulitis required.

CONCLUSION

Cellulitis is a complex diagnosis and has a variable clinical presentation at different stages. Although cellulitis is a common diagnosis to make, HCPs need to be mindful of alternative diagnoses.