Hemophagocytic lymphohistiocytosis and macrophage activation syndrome: two rare sides of the same devastating coin.

Hemophagocytic lymphohistiocytosis (HLH) is a rare genetic hyperinflammatory syndrome that occurs early in life. Macrophage activation syndrome (MAS) usually refers to a secondary form of HLH associated with autoimmunity, although there are other causes of secondary HLH, such as infections and malignancy. In this article, we reviewed the concepts, epidemiology, clinical and laboratory features, diagnosis, differential diagnosis, prognosis, and treatment of HLH and MAS. We also reviewed the presence of MAS in the most common autoimmune diseases that affect children. Both are severe diseases that require prompt diagnosis and treatment to avoid morbidity and mortality.

Painful ulcers in a 5-year-old girl.

A 5-year-old girl was admitted to our clinic with several painful ulcers spreading from the right elbow to the armpit. The right axillary lymph node was palpable. She was previously treated in another service with oral amoxicillin for 10 days due to a diagnosis of impetigo. There was no resolution of the lesion after the treatment, so she looked for another doctor.

Risk factors for the development of hospital-acquired pediatric venous thromboembolism-Dealing with potentially causal and confounding risk factors using a directed acyclic graph (DAG) analysis.

INTRODUCTION: Hospital-acquired venous thromboembolism (HA-VTE) in children comprises multiple risk factors that should not be evaluated separately due to collinearity and multiple cause and effect relationships. This is one of the first case-control study of pediatric HA-VTE risk factors using a Directed Acyclic Graph (DAG) analysis. MATERIAL AND METHODS: Retrospective, case-control study with 22 cases of objectively confirmed HA-VTE and 76 controls matched by age, sex, unit of admission, and period of hospitalization. Descriptive statistics were used to define distributions of continuous variables, frequencies, and proportions of categorical variables, comparing cases and controls. Due to many potential risk factors of HA-VTE, a directed acyclic graph (DAG) model was created to identify confounding, reduce bias, and increase precision on the analysis. The final model consisted of a DAG-informed conditional logistic regression. RESULTS: In the initial conventional univariable model, the following variables were selected as potential risk factors for HA-VTE: length of stay (LOS, days), immobility, ICU admission in the last 30 days, LOS in ICU, infection, central venous catheter (CVC), number of CVCs placed, L-asparaginase, heart failure, liver failure, and nephrotic syndrome. The final model using the set of variables selected by DAG analysis revealed LOS (OR = 1.106, 95%CI = 1.021-1.198, p = 0.013), L-asparaginase (OR = 26.463, 95%CI = 1.609-435.342, p = 0.022), and nephrotic syndrome (OR = 29.127, 95%CI = 1.044-812.508, p = 0.004) as independent risk factors for HA-VTE. CONCLUSION: The DAG-based approach was useful to clarify the influence of confounders and multiple causalities of HA-VTE. Interestingly, CVC placement-a known thrombotic risk factor highlighted in several studies-was considered a confounder, while LOS, L-asparaginase use and nephrotic syndrome were confirmed as risk factors to HA-VTE. Large confidence intervals are related to the sample size; however, the results were significant.

Hemophagocytic lymphohistiocytosis and macrophage activation syndrome: two rare sides of the same devastating coin

Abstract Hemophagocytic lymphohistiocytosis (HLH) is a rare genetic hyperinflammatory syndrome that occurs early in life. Macrophage activation syndrome (MAS) usually refers to a secondary form of HLH associated with autoimmunity, although there are other causes of secondary HLH, such as infections and malignancy. In this article, we reviewed the concepts, epidemiology, clinical and laboratory features, diagnosis, differential diagnosis, prognosis, and treatment of HLH and MAS. We also reviewed the presence of MAS in the most common autoimmune diseases that affect children. Both are severe diseases that require prompt diagnosis and treatment to avoid morbidity and mortality.

[Presence of riziform bodies in a patient with juvenile idiopathic arthritis: case report and literature review.] / Presença de corpos riziformes em paciente com artrite idiopática juvenil: relato de caso e revisão de literatura.

Riziform bodies are structures formed by fibrin and cells that can be found in the synovial fluid or attached to the synovium, and have this denomination due to its rice grain-like appearance. They have already been described in several diseases such as tuberculous arthritis, rheumatoid arthritis, and rarely in juvenile idiopathic arthritis (JIA). This is the case of a boy with a 4-month course of chronic monoarthritis of the left knee, with family history of sarcoidosis in which diagnostic investigation showed the presence of these riziform bodies in the synovial biopsy. Diagnostic investigation ruled out sarcoidosis, tuberculosis and malignancies, establishing the diagnosis of JIA. Our objective was to describe what we believe is the 9th case reported on the presence of riziform bodies in JIA, which are probably underdiagnosed, and should be considered mainly in cases of severe arthritis of difficult medical treatment.