Rheumatologic manifestations with elevated levels of IL-6, IL-17A, and IL-23 in a patient with scurvy.

Symptomatic vitamin C deficiency, scurvy, is a relatively rare disease in developed countries, but it has been reported in patients with autism spectrum disorder or developmental delay who tend to have selective diets. Patients with scurvy often demonstrate musculoskeletal manifestations with unknown pathophysiology. Herein, we report a case of scurvy in an 11-year-old boy who presented with iron-deficiency anaemia, systemic osteomyelitis, myositis predominantly in the lower extremities, and right ventricular volume overload with mild pulmonary hypertension and was diagnosed with scurvy. He had a mild developmental disorder and a selective diet, which resulted in severe vitamin C deficiency. He received intravenous and oral vitamin C supplementation, which relieved his arthralgia and muscle pain in a week. Following 4 months of vitamin C supplementation, he demonstrated no abnormal manifestations on laboratory or imaging examination and recovered without sequelae. Inflammatory cytokine and chemokine evaluations demonstrated elevated levels of interleukin (IL)-6, IL-17A, and IL-23, which are associated with T-helper (Th) 17 cell activation. This study is the first to suggest the association between the inflammation seen in scurvy, rheumatic manifestations in the patient, and Th17 cell activation. Further analysis of the association between the inflammation and vitamin C supplementation may contribute to new insights for the comprehension and treatment of other inflammatory diseases, such as rheumatic diseases.