BACKGROUND: Papular mucinosis is characterised by primary mucin deposition in the dermis. The classification distinguishes between the localised form and the systemic form, which alone can result in complications, but this classification occasionally proves to be inadequate. Herein we report the progression of papular mucinosis, initially atypical due to the absence of cutaneous sclerosis and of misleading granulomatous histological features, which subsequently developed into characteristic scleromyxedema.
METHODS: A 55-year-old male developed a rash comprising countless acral papules. Several biopsies were necessary before a diagnosis of papular mucinosis was made, due to the initial granulomatous appearance at histology. Tests showed monoclonal immunoglobulin of indeterminate significance, but, due to the absence of cutaneous sclerosis, we were able to conclude on typical localised papular mucinosis. Two years later, extensive sclerotic induration of the skin appeared and the diagnosis was modified to one of scleromyxedema. Treatment with intravenous immunoglobulins was given and proved efficacious, but relapse occurred on discontinuation of the therapy.
CONCLUSIONS: Papular mucinosis is a rare disease of unknown physiopathology. The disease classification distinguishes between the localised and systemic forms, but it occasionally proves to be inadequate. Our case suggests a continuum between the localised and systemic forms of the disease. Further, the initial biopsies of acral papules in our patient had a misleading granulomatous appearance, as has been reported numerous times for the systemic forms. This granulomatous histological variant thus appears to constitute a diagnostic criterion for scleromyxedema.

The finding of hardening and thickening of the skin is common and can be encountered in immune mediated, metabolic, neoplastic, toxic, genetic diseases, or associated with protein deposits. The lack of Raynaud\'s phenomenon, capillaroscopic abnormalities, or scleroderma-specific autoantibodies should question the diagnosis of scleroderma and trigger the search for a scleroderma-like disorder, for which treatment and prognosis differ. This article gives a review of these disorders and their main characteristics.

BACKGROUND: Dermato-neuro syndrome is a specific neurological complication of scleromyxedema presenting with fever, coma, seizures and flu-like syndrome. To our knowledge, it has only been reported about twenty times in the literature. Its outcome is uncertain. We describe the case of a patient in whom a favorable outcome was achieved using a combination of plasmapheresis and intravenous immunoglobulin (IVIG).
METHODS: A 57-year-old woman was diagnosed 14 years ago with scleromyxedema resistant to multiple lines of treatment. In November 2011, she presented an initial episode of epileptic seizure followed by post-seizure coma, and later, confusional state with visual hallucinations. She recovered spontaneously within a few days. CT scan, MRI, EEG and screening for infection were perfectly normal, resulting in suspicion of neurological involvement associated with her scleromyxedema. In December 2012 and August 2013, she presented two further episodes of status epilepticus, followed once more by a confusional state, with etiological explorations again proving unfruitful. On this occasion, her confusional state persisted for two months until the initiation of plasmapheresis and IVIG. This combination therapy led to rapid regression of all neurological symptoms and an improvement in her general condition.
CONCLUSIONS: The dermato-neuro syndrome is a rare neurological complication of scleromyxedema. Its pathophysiology is unknown. The monoclonal gammopathy induced by the scleromyxedema could account for the patient\'s hypercoagulable state and for the formation of neutrophilic aggregates leading to impaired microcirculation. Treatment is empirical and poorly codified. The course of the disease is unpredictable and may be lethal.