[The significance of extra-articular manifestations for the differential diagnosis of musculoskeletal diseases in children].

Musculoskeletal complaints comprise about 7% of all pediatric office visits. The differential diagnosis of these complaints is very extensive. A great diagnostic aid offer quality, distribution and temporal course of the pain of joints, bone and muscles, of an objectively detectable arthritis, and especially of the numerous manifestations of other organ systems: Constitutional signs, fever, skin, mucous membranes, eyes, nervous system, heart, vasculature, lungs, digestive system and urogenital system. Combinations of these often early manifestations are crucial to determine the disease category, which is urgent for further diagnostic measures and for therapy: Bacterial, rheumatic, collagen-vascular, traumatic, orthopedic, and neoplastic disease. They are as important for making the final diagnosis and for the early recognition of later manifestations and complications. To achieve an optimal diagnostic efficiency, laboratory investigations should be carefully selected according to the clinical findings and diagnoses. A few regular investigations are valuable for the assessment of disease activity and therapy, and others for the early detection of initially asymptomatic manifestations.