Truss-induced macular amyloidosis

A 80-year-old male presented with a long time history of a localized red-br own macule with superficial lichenification and slight scaling in the right groin. An earlier skin biopsy revealed the presence of amyloid deposits. T he patient therefore had a complete internal checkup including a rectal bio psy for exclusion of systemic amyloidosis. However, the laboratory data did not reveal any specific abnormalities including immunoglobulins and Bence- Jones protein. The rectal biopsy was also nonspecific. After skin examinati on, a rebiopsy was performed at our department showing acanthosis and spong iosis of the epidermis with parakeratosis. A homogenous eosinophilic deposi t was present in the upper dermis and stained positive with thio-flavine. A t the second visit the patient wore a truss for a right inguinal hernia, pe rfectly matching the area of the skin lesion. Thus, the diagnosis of a loca lized macular amyloidosis was confirmed very likely due to permanent local friction. The classification of localized cutaneous amyloidoses should include local trauma as a cause to avoid unnecessary and exhausting internal checkups to exclude systemic involvement.