P10 Inflammatory bone lesions and inflammatory arthritis in a young girl with autosomal dominant anhidrotic ectodermal dysplasia with immune deficiency

Abstract

Background: Anhidrotic ectodermal dysplasia with immune deficiency is a genetic disorder characterised by the absence of sweat glands, conical-shaped teeth, immunosuppression and certain facial, skin and hair abnormalities. The autosomal dominant form is caused by a mutation in the NFKB1A gene, which disrupts NF-kB-mediated activation of genes involved with inflammation, immunity and cell survival. There have only been 14 cases of the autosomal dominant form described in the literature. The association between primary immunodeficiency and an increased risk of autoimmune disease is well established. Consistent with this, inflammatory bowel disease and juvenile idiopathic arthritis (JIA) have been described in autosomal dominant EDA-ID. Here, we report the first case of a young girl with autosomal dominant EDA-ID with involvement of both inflammatory bone and joint disease. Methods: Please see the results section below. Results: The patient first presented with bilateral knee synovitis. Given the underlying immunodeficiency this was felt to be of infectious origin and she was started on intravenous antibiotics. Synovial biopsy confirmed synovitis, however, cultures remained negative for organisms. Therefore, she underwent several intra-articular steroid injections which effectively improved her synovitis. This later evolved into polyarticular synovitis for which she was started on methotrexate with a good response. However, she subsequently developed left hip pain with an associated antalgic gait. X-ray identified a bone lesion in the left femoral epiphysis and metaphysis and whole body MRI identified a wider bone involvement. Culture of these lesions was also negative, suggesting an inflammatory aetiology. Conclusion: Although autoimmunity and autoinflammation have been described in EDA-ID, the presence of inflammatory bone and joint disease has not been formally reported and is a potentially rare complication. We aim to characterise this manifestation and discuss potential management strategies.