Synovitis–acne–pustulosis–hyperostosis–osteitis (SAPHO) syndrome is a rare disease characterized by a sterile inflammatory osteitis and/or arthritis associated with a wide range of dermatological manifestations, such as acne, palmoplantar pustulosis, and psoriasis. This review, providing up-to-date knowledge on this disease, aims at informing researchers and clinicians to help them program future studies in order to improve patients’ care. Due to the vast clinical heterogeneity that characterizes this disease, SAPHO syndrome has received various names; among these, chronic recurrent multifocal osteomyelitis represents the most used one. The various nomenclatures in use also reflect different approaches to its management. Indeed, considering the world-wide distribution and the vast onset age (from children to late adulthood), in addition to the multiform clinical presentation, its diagnosis and treatment are often challenging for clinicians. In this review, we provide valuable insights on SAPHO syndrome, delving into its many aspects: epidemiology, pathogenesis, clinical presentation, diagnosis, and classification. Most importantly, this paper addresses the continuously changing treatment panorama of this disease, from established drugs to newly introduced ones. Furthermore, a peculiar focus regards nonpharmacologic approaches, including traditional Chinese medicine, the apheresis technique, and surgery. Similarly, this review also discusses patients’ lifestyle, including quality of life. To improve SAPHO syndrome’s management, different knowledge gaps should be filled, such as its current epidemiology and pathogenesis. In turn, perfected knowledge in these fields could also advance research in therapy.

Introduction: Systemic JIA (sJIA), a multifaceted autoinflammatory disorder, can be complicated by life-threatening conditions such as macrophage activation syndrome (MAS) and interstitial lung disease. The management of these conditions presents a therapeutic challenge, underscoring the need for innovative treatment approaches. Objectives: To report the possible role of MAS825, a bispecific anti-IL1β and IL-18 monoclonal antibody, in the treatment of multi-drug-resistant sJIA. Methods: We report two patients affected by sJIA with severe and refractory MAS and high serum IL-18 levels, responding to dual blockade of IL-1β and IL-18. Results: The first patient is a 20-year-old man, presenting a severe MAS complicated by thrombotic microangiopathy, following SARS-CoV-2 infection. He was treated with MAS825, with quick improvement. Eighteen months later, the patient is still undergoing biweekly treatment with MAS825, associated with MTX, ciclosporin and low-dose glucocorticoids, maintaining good control over the systemic features of the disease. The second patient, a 10-year-old girl, presented a severe MAS case, complicated by posterior reversible encephalopathy syndrome, following an otomastoiditis. The MAS was not fully controlled despite treatment with i.v. high-dose glucocorticoids, anakinra and ciclosporin. She began biweekly MAS825, which led to a prompt amelioration of MAS parameters. After 10 months, the patient continues to receive MAS825 and is in complete remission. Conclusion: In light of the pivotal role of IL-1β and IL-18 in sJIA, MAS and interstitial lung disease, MAS825 might represent a possible valid and safe option in the treatment of drug-resistant sJIA, especially in the presence of high serum IL-18 levels.

Zinc deficiency is a significant global health concern among children, manifesting in various acquired and inherited conditions. This comprehensive overview of acquired and inherited zinc deficiency-related diseases in children aimed to explore the clinical presentations, diagnostic challenges, and management strategies associated with these conditions. This case series elucidates the diverse clinical manifestations of zinc deficiency in pediatric patients, ranging from dermatitis and growth retardation to immune dysregulation and neurological abnormalities, and discusses the underlying genetic mechanisms, clinical phenotypes, and therapeutic interventions. The complexity of zinc deficiency-related diseases in children underscores the need for a multidisciplinary approach involving pediatricians, dermatologists, geneticists, and nutritionists to optimize patient care and outcomes.

To evaluate whether the heterogeneous skin manifestations might influence the disease presentation and outcome of a cohort of SAPHO children. the clinical, serological, imaging and therapeutic data of 14 SAPHO patients, followed between 2001 and 2022 at the Unit for Autoinflammatory diseases at the Gaslini Hospital, were reviewed. According to their cutaneous manifestations, patients were divided into 2 groups: the acne-hidradenitis suppurativa (HS) and the Palmo-Plantar Pustulosis (PPP) group. Data were retrieved from the Eurofever database. all patients presented bone involvement characterized by Chronic Recurrent multifocal Osteomyelitis (CRMO): 8 patients presented acne-HS while 6 patients had PPP. In the PPP group, all patients were female, characterized by a prepuberal disease onset with osteoarticular manifestations, followed by the appearance of PPP in the following 6 months. This group responded well to the treatments. In the acne-HS group, 7/8 patients were male: the disease onset was characterized by skin manifestations in pubertal age, followed by osteoarticular manifestations in the following year. This group presented a severe refractory skin disease that required in most cases the addition of biological therapies. A literature review confirmed our data highlighting the association males-acne-puberal age and female-PPP-prepuberal age. paediatric SAPHO patients should be mainly stratified according to their skin involvement. In fact, our data suggest that two different skin phenotypes may be identified in SAPHO: the first is constituted by prepuberal females with PPP and a prevalent osteoarticular involvement, while the second by puberal males with a difficult-to-treat acne-HS.

Granulomatosis with polyangiitis (GPA) is an antineutrophil cytoplasmic antibody-associated vasculitis. The 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology (ACR/EULAR)-endorsed classification criteria for GPA was derived using data only from adult patients. We aimed to assess the performance of the ACR/EULAR classification criteria for GPA in pediatric patients and compare it with the EULAR/Pediatric Rheumatology International Trials Organization (PRINTO)/Pediatric Rheumatology European Society (PReS)-endorsed Ankara 2008 criteria for GPA. Retrospective data of pediatric patients with GPA in 20 centers from 9 countries were evaluated. The diagnosis of GPA was made according to the expert opinion. The sensitivity, specificity, positive predictive value, and negative predictive value of the criteria sets were evaluated. The study included 77 patients with GPA and 108 controls (immunoglobulin A vasculitis (n = 44), Takayasu’s arteritis (n = 20), microscopic polyangiitis (n = 16), polyarteritis nodosa (n = 14), Behçet's disease (n = 12), eosinophilic granulomatosis with polyangiitis (n = 1), and Cogan's syndrome (n = 1)) with a median age of 17.8 and 15.2 years, respectively. Of patients with GPA, constitutional symptoms (85.7%) and ear-nose-throat involvement (79.2%) were the most common presentations. In the GPA group, 73 patients fulfilled the Ankara 2008 criteria and 69 the ACR/EULAR classification criteria. Sensitivities of the Ankara 2008 criteria and the ACR/EULAR classification criteria were 94.8% and 89.6%, while specificities were 95.3% and 96.3%, respectively. No significant difference was found between sensitivities and specificities of both classification criteria (p= 0.229 and p= 0.733, respectively). In children, both the ACR/EULAR and EULAR/PRINTO/PReS Ankara 2008 classification criteria for GPA perform well and similarly.