BI34 Scleromyxoedema in pregnancy: a rare and complex case

Abstract A 38-year-old woman presented with a 2-year history of progressively worsening, firm, flesh-coloured papules and plaques affecting her face, neck, trunk and limbs. She reported skin tightening, reduced mobility and pruritus. For 6 months she had experienced dysphagia and sore muscles. In the private sector she had been prescribed high-dose oral corticosteroids and ciclosporin, with no improvement. A skin biopsy revealed mucin deposition, fibroblast proliferation and fibrosis in the dermis. Laboratory evaluation identified an IgG lambda monoclonal gammopathy, meeting the diagnostic criteria for scleromyxoedema. Other blood tests were normal, including creatine kinase, and Bence Jones proteins were not detected. Six weeks after her diagnosis, the patient discovered she was pregnant. Further investigations such as a computed tomography–positron emission tomography scan and bone marrow biopsy were thus halted. Cardiac investigations including electrocardiogram and transthoracic echocardiogram were normal. Following multidisciplinary discussion and counselling with the maternal medicine, local oncology and regional dermato-oncology teams she opted to continue the pregnancy and her treatment plan was adapted to balance disease control with fetal safety. The speech and language therapy team assessed her swallowing and she was seen by dieticians and commenced on liquid supplements. Scleromyxoedema has recently been added to the limited number of conditions for which intravenous immunoglobulin (IVIg) is indicated in the UK. In view of her pregnancy no other treatments were considered. Twelve weeks into her pregnancy she experienced some mild softening of the skin on her limbs, but despite this it was felt that IVIg should be commenced, and at 15 weeks she started monthly infusions. Subcutaneous low-molecular-weight heparin was started daily to reduce the risk of thromboembolism. So far the pregnancy has been uneventful, except for the development of gestational diabetes mellitus. Scleromyxoedema is a rare fibromucinous disorder with potential systemic involvement and significant management challenges, particularly during pregnancy. This case underscores the importance of respecting patient autonomy while navigating complex clinical decisions. Pregnancy-related hormonal and immune changes may influence disease activity, although the impact remains poorly understood. To date there is one reported case of scleromyxoedema in pregnancy and our case adds to the limited literature, highlighting the need for individualized, multidisciplinary approaches. This case illustrates the successful management of scleromyxoedema, so far, during pregnancy. However, the long-term prognosis in this patient remains uncertain.