Association of skin with the pathogenesis and treatment of neurodegenerative amyloidosis

Amyloidosis are a large group of conformational diseases characterized by abnormal protein folding and assembly which results in the accumulation of insoluble protein aggregates that may accumulate systemically or locally in certain organs or tissue. In local amyloidosis, amyloid deposits are restricted to a particular organ or tissue. Alzheimer’s, Parkinson’s disease, and amyotrophic lateral sclerosis are some examples of neurodegenerative amyloidosis. Local manifestation of protein aggregation in the skin has also been reported. Brain and skin are highly connected at a physiological and pathological level. Recently several studies demonstrated a strong connection between brain and skin in different amyloid diseases. In the present review, we discuss the relevance of the “brain–skin connection” in different neurodegenerative amyloidosis, not only at the pathological level, but also as a strategy for the treatment of these diseases.

The blue man: a novel cutaneous manifestation of systemic amyloidosis

Multiple cutaneous manifestations of amyloidosis have been described, and include periorbital purpura, plaques, nodules, and papules. Blue skin tint is not a previously described feature of cutaneous amyloidosis. We report the clinical case of a patient with known multiple myeloma and amyloidosis of the gastrointestinal tract who presented with progressive "blueness" of the skin. Dermatopathological examination and mass spectrometry of a skin biopsy specimen revealed the presence of subcutaneous amyloid light chain (AL) deposition. We believe this to be the first reported case of blue skin resulting from systemic amyloidosis.