The term septic arthritis refers to an infection of the synovial space. This is an infrequent condition in healthy children, but it should be considered a medical emergency potentially leading to irreversible articular damage. Therefore, prompt diagnosis and antimicrobial treatment play a crucial role in improving the prognosis. Although septic arthritis is the most common cause of acute arthritis, many other diseases may mimic a similar clinical picture, constituting a diagnostic challenge for the clinician who first approaches the patient. Herein we analyze the main features of septic arthritis, offering an overview of the main conditions involved in the differential diagnosis and suggesting a diagnostic workup plan.

Lacrimal gland inflammation, known as dacryoadenitis, is an uncommon condition with various etiologies, ranging from infectious to autoimmune diseases. The clinical course can be acute, subacute, or chronic, with involvement on one or both sides. In the course of mononucleosis, a self-limited eyelid edema is often observed, while dacryoadenitis has been rarely reported. We present the case of an 8-year-old girl with bilateral subacute Epstein–Barr virus-induced dacryoadenitis, who underwent orbital magnetic resonance imaging and gland biopsy, and we performed a comprehensive literature review.

Background: Autoinflammatory bone disorders are rare, non-infectious inflammatory conditions that primarily involve the skeleton, most commonly presenting as chronic nonbacterial osteomyelitis (CNO) or chronic recurrent multifocal osteomyelitis (CRMO). Less frequently, they occur in the context of Mendelian syndromes such as Majeed syndrome, deficiency of the interleukin-1 receptor antagonist (DIRA), and pyogenic arthritis; pyoderma gangrenosum; and acne (PAPA) syndrome. Given the role of IL-1-driven innate immune dysregulation across these bone disorders, and the growing, though heterogeneous, clinical experience with IL-1 blockade, this review maps and critically appraises the available evidence on canakinumab in autoinflammatory bone disorders. Methods: We systematically searched PubMed and the Cochrane Library (English, inception–July 2025) and screened ClinicalTrials.gov. Eligible reports included any case reports/series describing canakinumab use in autoinflammatory bone disorders (CNO/CRMO, Majeed, DIRA, PAPA). Results: Six publications met the inclusion criteria (one case series, five case reports; 10 patients). Complete responses were reported in all three patients with Majeed syndrome and in two patients with sporadic CRMO associated with systemic features. Partial responses occurred in two additional sporadic CRMO cases, while no meaningful response was documented in DIRA. No interventional trials of canakinumab were identified on ClinicalTrials.gov for CNO/CRMO, Majeed, DIRA, or PAPA. Conclusions: Although the role of IL-1 in the pathogenesis of autoinflammatory bone disease provides a rationale for IL-1 blockade, evidence for canakinumab remains limited and heterogeneous, precluding definitive conclusions. Indicators of benefits appear most consistently in Majeed syndrome and in selected CRMO phenotypes.

Background: Scurvy is an uncommon and often underrecognized disease. However, conditions associated with a restrictive and/or selective diet and inadequate absorption still pose a high risk for developing vitamin C deficiency. Musculoskeletal symptoms are among the most characteristic manifestations of scurvy, often requiring radiological investigations. Objective: This study aims to describe the radiological signs of scurvy on pelvic magnetic resonance imaging (MRI) in children presenting with musculoskeletal symptoms and to highlight features that may help differentiate it from other conditions with similar presentations. Methods: We conducted a retrospective study including children admitted for musculoskeletal symptoms requiring a pelvic MRI and who were subsequently diagnosed with scurvy. Demographic, clinical, laboratory, and radiological data were extracted from electronic medical records. Results: We identified ten patients with a median age at disease onset of 45 months (range 17–133 months) admitted between 2016 and 2022. All ten patients included in the study were male. All had at least one of the following symptoms: limping, pain in the lower limbs, or refusal to walk, in addition to gum bleeding (7/10), hypertrophic gums (5/10), purpura (3/10), irritability (3/10), and fever (2/10). In all patients, pelvic MRI showed a bilateral, patchy, abnormal, water-like signal intensity pattern in the sacroiliac area. Sacroiliitis was detected in three children and hip effusion in another child. Seven out of these ten patients had a previous pelvis X-ray that was negative. Conclusions: In scurvy, the pelvis is often prematurely affected, with bone marrow accumulating water and joints showing inflammatory changes, particularly at the hips and sacroiliac joints. Due to its ability to assess soft tissues and its high sensitivity to water content, MRI is the ideal imaging tool to assess these changes. In contrast, plain radiography is less sensitive and specific and may be uninformative in the early stages of the disease.