[Scleromyxedema]. / Skleromyxödem.

Scleromyxedema or generalized diffuse lichen myxoedematosus is a rare mucinosis that is associated with monoclonal gammopathy and which frequently affects multiple extracutaneous organ systems. The pathogenesis of scleromyxedema has not been fully elucidated, but includes stimulation of glycosaminoglycan synthesis. The clinical course of scleromyxedema is chronic and often progressive, leading to severe morbidity and even death. The characteristic skin findings encompass multiple waxy papules often on indurated plaques, while thickening of skin leads to conspicuous folds on glabella and dorsal aspects of finger joints. Microscopical manifestations are dermal deposits of glycosaminoglycans between collagen bundles in reticular dermis, increased numbers of fibroblasts and fibrosis as well as loss of elastic fibers. Progressive skin involvement results in decreased mobility of the mouth and joints and even contractures. Extracutaneous manifestations occur in the musculoskeletal or cardiovascular system, in the gastrointestinal or respiratory tract, in the kidneys or in the central and peripheral nervous system. There are no in-label or evidence-based treatments available for scleromyxedema, but by expert consensus high-dose immunoglobulins are considered as treatment of choice, followed in case of insufficient efficacy by systemic glucocorticosteroids and then lenalidomide or thalidomide. In severe and refractory cases, autologous hematopoietic stem cell transplantation has been performed. Long-term maintenance treatment is usually required to prevent recurrences. Close interdisciplinary follow-up is recommended.

Papular Mucinosis.

This case report describes erythematous patches on the face that involved the nasolabial folds, as well as numerous skin-colored homogenous waxy papules on the arms, neck, and trunk.

Dermato-neuro syndrome after COVID-19 infection in a patient with scleromyxoedema: Previously successful treatment with intravenous immunoglobulins.

Scleromyxedema (SMX) is a rare disease of unknown cause. It is a chronic, progressive, metabolic disorder characterized by a generalized papular and scleroderma-like rash, as well as a subtype of lichen myxedematosus. Dermato-neuro syndrome (DNS) is a rare neurological complication of SMX. It has flu-like prodromal symptoms; consists of a triad of fever, coma, and seizures; and can be life-threatening. We describe a patient with SMX complicated by DNS after infection with COVID-19. Her symptoms resolved after treatment with acyclovir and low-dose glucocorticoids, suggesting that DNS seizures may have a viral cause. Her skin lesions also improved after seven courses of intravenous immunoglobulin treatment, confirming that intravenous immunoglobulin is effective in these cases.

Nodular-Type Lichen Myxedematosus: A Rare Variant With Exclusive Involvement of the Hands-Report of Two Cases With a Comprehensive Review of the Literature.

ABSTRACT: Lichen myxedematosus (LM) is an uncommon cutaneous mucinosis characterized by the deposition of mucin and fibroblast proliferation in the dermis. This condition can be classified into 2 forms: a diffuse/generalized LM, also known as scleromyxedema, associated with monoclonal gammopathy and systemic implications, and a localized form, primarily affecting the skin. Within the localized form, nodular-type LM is a rare variant presenting as firm, skin-colored to pinkish mucinous nodules. In this article, we report 2 new cases of nodular-type LM with exclusive involvement of the hands and provide a comprehensive review of the diagnosis, histopathological aspects, and therapeutic considerations of this rare condition.

[Dermato-neuro syndrome-an acute and life-threatening complication of scleromyxedema Arndt-Gottron]. / Dermato-neurologisches Syndrom ­ eine akute und lebensbedrohliche Komplikation des Skleromyxödems Arndt-Gottron.

Scleromyxedema Arndt-Gottron is the systemic variant of lichen myxedematosus in which mucin accumulation occurs in the dermis. The disease is usually chronically progressive and extracutaneous manifestations or complications are possible. The pathogenesis is unknown and the disease is usually associated with monoclonal gammopathy. High-dose intravenous immunoglobulins (IVIg) are considered to be an effective therapy. We report the case of a patient who developed dermato-neuro syndrome following an interruption of IVIg treatment and a SARS-CoV­2 infection. A similar episode occurred 2 years earlier in association with an influenza A infection. Dermato-neuro syndrome is a potentially lethal neurological complication which is characterized by fever, delirium, convulsions, and coma.

Generalized Muscular Uptake of 99m Tc-MDP on Bone Scan in a Patient With Scleromyxedema-Associated Myopathy.

ABSTRACT: A 62-year-old man presented with a 5-year history of progressive myasthenia, myalgia, and skin changes. Upon laboratory testing, elevated serum creatine kinase and lactate dehydrogenase, as well as monoclonal immunoglobulin Gκ, were observed. A bone scan revealed generalized muscular uptake of 99m Tc-MDP, whereas 18 F-FDG PET/CT demonstrated only mild hypermetabolism of the muscles. A muscle biopsy showed myofibrillary vacuolar degeneration, and a skin biopsy indicated scleromyxedema. Based on these findings, the patient was diagnosed with scleromyxedema-associated myopathy.

Identifying the potential origin of mucin in primary cutaneous mucinoses-A retrospective study and analysis using histopathology and multiplex fluorescence staining.

BACKGROUND: Primary cutaneous mucinoses (PCM) are rare diseases characterized by dermal or follicular mucin deposits. OBJECTIVES: A retrospective study characterizing PCM to compare dermal with follicular mucin to identify its potential origin on a single-cell level. MATERIAL AND METHODS: Patients diagnosed with PCM between 2010 and 2020 at our department were included in this study. Biopsy specimens were stained using conventional mucin stains (Alcian blue, PAS) and MUC1 immunohistochemical staining. Multiplex fluorescence staining (MFS) was used to investigate which cells were associated with MUC1 expression in select cases. RESULTS: Thirty-one patients with PCM were included, 14 with follicular mucinosis (FM), 8 with reticular erythematous mucinosis, 2 with scleredema, 6 with pretibial myxedema and one patient with lichen myxedematosus. In all 31 specimens, mucin stained positive for Alcian blue and negative for PAS. In FM, mucin deposition was exclusively found in hair follicles and sebaceous glands. None of the other entities showed mucin deposits in follicular epithelial structures. Using MFS, all cases showed CD4+ and CD8+ T cells, tissue histiocytes, fibroblasts and pan-cytokeratin+ cells. These cells expressed MUC1 at different intensities. MUC1 expression in tissue histiocytes, fibroblasts, CD4+ and CD8+ T cells, and follicular epithelial cells of FM was significantly higher than the same cell types in the dermal mucinoses (p < 0.001). CD8+ T cells were significantly more involved in expression of MUC1 than all other analysed cell types in FM. This finding was also significant in comparison with dermal mucinoses. CONCLUSION: Various cell types seem to contribute to mucin production in PCM. Using MFS, we showed that CD8+ T cells seem to be more involved in the production of mucin in FM than in dermal mucinoses, which could indicate that mucin in dermal and follicular epithelial mucinoses have different origins.

Renal injury in scleromyxoedema due to monoclonal gammopathy associated C3 glomerulonephritis.

Scleromyxoedema is a rare mucinosis that primarily affects the skin. It is associated with monoclonal gammopathy and has many extracutaneous manifestations, however, renal involvement is rare. We report the case of a woman with monoclonal gammopathy and scleromyxoedema presenting with progressive exertional dyspnoea and acute renal failure. Workup of her renal failure revealed monoclonal gammopathy associated C3 glomerulonephritis. She was treated with intravenous steroids and discharged with plans to pursue annual monoclonal gammopathy laboratory monitoring. Given the rarity of renal scleromyxoedema, careful investigation of extracutaneous manifestations and comorbidities is critical to discern the primary pathological process in patients with scleromyxoedema who develop renal insufficiency.