The incidence in pediatrics is very low (about 3.5 per million per year according to a 2015 study) and therefore the data on the pathology very poor, especially on the therapeutic level.

Without appropriate treatment, the disabling sequelae, even involving the vital prognosis, are significant. However, in paediatrics, therapeutic habits have been extrapolated from adult data and lack precision.

Existing treatments are almost composed of immunomodulatory and/or immunosuppressive treatments. Different therapeutic lines have been introduced over the years and a better understanding of the pathology. More recently, biotherapies have been introduced in this pathology, but data on their effectiveness remain limited. Data on the evolution under therapy in children are thus still poor.

Complications related to the pathology that can jeopardize the vital prognosis and the response to treatment for this pathology deserve to be studied in order to be known and if possible avoided.

The aim of the study is to describe French practices and compare the lines of treatment proposed for juvenile atrophic polychondritis.

Inclusion criteria:

• Minor subject aged 1 to 17 years
• Diagnosis of atrophic polychondritis between 01/01/2008 to 31/12/2022.
• Subject (and/or his parental authority) who has not expressed, after being informed, his opposition to the reuse of his data for the purposes of this research.

Exclusion criteria:

• Subject (or his parents) having expressed his (their) opposition to participating in the study
• Associated pathologies that cannot be related to the diagnosis of atrophic polychondritis and whose prognosis can lead to biases in the efficacy and/or complications related to treatments.

Minor subject aged 1 to 17 years having atrophic polychondritis