Primary localized cutaneous lichen myxedematosus with light chain-restricted plasma cells: A distinct variant of the localized form of lichen myxedematosus.

Lichen myxedematosus (LM) is a chronic cutaneous mucinosis that can present as a localized skin lesion or as a generalized systemic disease termed scleromyxedema. The differential diagnosis is determined by a combination of clinical presentation, serological studies, and histopathological examination. Currently, well-established and accepted histopathological features to distinguish localized LM from scleromyxedema have not been elucidated. Our recent publication, together with a retrospective literature review, suggests that the presence of groups of light chain-restricted plasma cells represents a distinct histopathological clue for the diagnosis of localized LM. In this report, we provide two additional cases of localized LM with lambda light chain-restricted plasma cells, together with clinical and histopathological findings that are similar to our previous publication. These cases support our theory that the light chain-restricted plasmacytic microenvironment is primarily attributed to the pathogenesis of localized LM. Therefore, we consider these cases to constitute a clinically and pathologically new variant of localized LM and name it primary localized cutaneous LM with light chain-restricted plasma cells.

Consensus statement on the diagnosis and treatment of sclerosing diseases of the skin, Part 2: Scleromyxoedema and scleroedema.

The term 'sclerosing diseases of the skin' comprises specific dermatological entities, which have fibrotic changes of the skin in common. These diseases mostly manifest in different clinical subtypes according to cutaneous and extracutaneous involvement and can sometimes be difficult to distinguish from each other. The present consensus provides an update to the 2017 European Dermatology Forum Guidelines, focusing on characteristic clinical and histopathological features, diagnostic scores and the serum autoantibodies most useful for differential diagnosis. In addition, updated strategies for the first- and advanced-line therapy of sclerosing skin diseases are addressed in detail. Part 2 of this consensus provides clinicians with an overview of the diagnosis and treatment of scleromyxoedema and scleroedema (of Buschke).

[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.