This editorial commentary reviews and discusses the article by Parri et al., “Procalcitonin in Pediatric Emergency Medicine” (Advances in Pediatrics, 2025, in press), which analyzes the role of procalcitonin (PCT) as a diagnostic biomarker in pediatric emergency departments. Based on that review, the main clinical implications are presented, and the applicability of PCT in different pediatric infectious scenarios is evaluated.

The most relevant aspects of the article, its clinical jus­tification, and the rigor of the available evidence are sum­marized below.

Justification

Fever-related visits in pediatrics often lead to diagnos­tic testing and empirical treatments, even though most cases are viral in origin and only a minority result in severe bacterial complications. Nevertheless, deterioration and life-threatening risk associated with bacterial infections— especially in very young children, many of them with few symptoms—can progress rapidly. This context highlights the need to improve risk stratification, thus avoiding the overuse of antibiotics and invasive procedures.

For years, clinicians have sought a test that could im­mediately and accurately determine when a bacterial in­fection is present and allow risk categorization. In recent decades, interest has focused on inflammatory biomarkers to discriminate between viral and bacterial etiologies and to predict the risk of infection. The article provides solid justification: the introduction of reliable biomarkers such as PCT can optimize clinical decision-making, with particular impact in young children, where the bacterial–viral differ­ential diagnosis remains a major challenge.

Among inflammatory markers, PCT stands out due to its rapid response and reasonable sensitivity and specifici­ty. Both the initial measurement and its follow-up help re­duce unnecessary antimicrobial use, positively influencing the control of multidrug-resistant pathogens.

The measurement of procalcitonin (PCT) is a use­ful tool, but its value must always be interpreted with­in the clinical context, prioritizing the clinician’s global diagnostic impression of the patient. Its use is directly linked to strategies aimed at reducing unnecessary anti­biotic prescriptions and, consequently, the emergence of multidrug-resistant organisms—a growing and critical problem in our healthcare environment. Additionally, it supports risk stratification in pediatrics, although such strategies must be adapted to the epidemiological char­

acteristics of each region, where differences in vaccination program adherence influence infection etiology.

Although PCT measurement is a rapid and simple pro­cedure, its high cost in some Latin American countries may limit its implementation. Nevertheless, the cost–benefit ra­tio is favorable if the savings associated with reduced hos­pitalizations, decreased unnecessary antibiotic treatments, and the positive impact on healthcare systems are consid­ered. Furthermore, it allows safe identification of low-risk pediatric patients, potentially avoiding hospital admissions and invasive procedures; however, in settings with socio­economic barriers, lack of adequate outpatient follow-up may necessitate hospitalization to ensure controlled clin­ical evolution.

Validity and scientific rigor

This narrative review supports its arguments with nu­merous primary studies and recent meta-analyses, many of them multicenter, as well as updated consensus state­ments and guidelines. It presents sensitivity and specificity figures for PCT in various scenarios, along with data on re­

duced unnecessary interventions in impact studies. It ana­lyzes PCT’s strengths (rapid rise, decrease after adequate infection control, superior early diagnostic performance compared with CRP) but also its limitations (does not re­place clinical judgment, variable performance depending on condition and cut-off values, limited specificity when used alone).

The article also reports its funding source (Thermo Fisher Scientific) and declares no conflicts of interest among the authors, although industry sponsorship should be considered in critical appraisal.

Clinical relevance

PCT has demonstrated practical importance in specific areas:

• Improves the specificity of screening strategies and re­duces invasive actions (e.g., lumbar punctures, hospital admissions) when used in combined algorithms for fe­brile infants

• In pediatric UTI, it better predicts acute pyelonephritis and vesicoureteral reflux than CRP and helps select pa­tients who may avoid unnecessary cystography

• Provides prognostic value in sepsis and pneumo­nia, helping tailor treatment intensity and antibiotic duration

• For osteoarticular infections, evidence on PCT remains limited and less conclusive, but suggests potential utility in distinguishing pyogenic

from nonpyogenic etiologies

Applicability in clinical practice

The article recommends adopting standardized proto­cols for PCT use, clinician training, and ongoing research. It explains that the greatest utility of PCT is achieved when combined with clinical assessment, urinalysis, and other markers, not as a standalone tool. It notes that low PCT lev­els may help rule out serious bacterial infection and reduce interventions, whereas elevated levels must be interpreted in context. It emphasizes the role of PCT in antimicrobial stewardship programs and in shared decision-making with families.

Critical appraisal

This article stands out for its pragmatic and up-to-date approach to the application of PCT in real-world pediat­ric emergency care. Its strengths include a comprehensive perspective that goes beyond diagnostic analysis and em­phasizes the impact on clinical management and rational antibiotic use. As a limitation, being a narrative review, it carries potential selection bias in reference choice; and although it is thorough, a structured analysis of evidence quality by indication would have strengthened the review. Industry sponsorship should be acknowledged, although it is transparently declared and appears not to have influ­enced the analysis directly.

In conclusion, this is a useful and applicable review for clinical practice, especially in pediatric emergency settings where diagnostic uncertainty and prudent antimicrobial use are paramount.