Introduction Skeletal dysplasias are disorders characterized by developmental abnormalities of the skeleton. They form a large heterogeneous group and range in severity from precocious osteoarthropathy to perinatal lethality. , Disproportionate short stature is the most frequent clinical complication but is…
Normal Skeletal Composition The complex structure and composition of bone is directly related to the two primary functions of the skeleton: to support the tissues of the body in order to permit locomotion and to provide a reservoir of ions…
Introduction One of the challenges of pediatric rheumatology is the broad spectrum of conditions ranging from the benign to the potentially life-limiting childhood malignancies that may present with relatively nonspecific musculoskeletal symptoms and signs. The importance of careful history taking,…
Acknowledgment The authors and editors acknowledge the contributions of the authors of this chapter in the 7th edition of the Textbook of Pediatric Rheumatology, Drs. Rubén Burgos-Vargas and Janitzia Vázquez-Mellado. This chapter is dedicated to the memory of Elia Ayoub,…
Lyme arthritis was first described in 1977 by Steere et al. in a cluster of children thought to have juvenile rheumatoid arthritis. They lived in and around Old Lyme, Connecticut. Subsequent studies documented that the disease was caused by the Ixodes…
Musculoskeletal infections are a significant cause of morbidity and mortality in children worldwide, and their early diagnosis is often critical. Acute infections may present clinically as osteomyelitis, septic arthritis, osteomyelitis combined with septic arthritis, spondylodiscitis, or pyomyositis. Acute osteomyelitis is…
Introduction Immunological derangements are recognized to play a significant role in the pathogenesis of rheumatic diseases in children, and primary immunodeficiency disorders (PIDDs) or inborn errors of immunity (IEIs) can occasionally be identified in children who have otherwise typical juvenile…
Definition Macrophage activation syndrome (MAS) is a severe, potentially fatal complication of rheumatic diseases caused by excessive activation and expansion of macrophages and T cells, leading to an overwhelming inflammatory reaction. The main manifestations of MAS include fever, hepatosplenomegaly, lymphadenopathy,…
Pediatric sarcoidosis encompasses a spectrum of childhood granulomatous inflammatory conditions, with the hallmark being the presence of noncaseating epithelioid giant cell granulomas in a variety of tissues and organ systems. The finding in 2001 of a mutation in the nucleotide-binding…
Autoinflammatory Bone Diseases Overview Autoinflammatory disorders (covered extensively in Chapter 39 ) result from aberrant and/or spontaneous activation of components of the innate immune system. , At least initially, they occur in the absence of high titer autoantibodies or autoreactive…