ABSTRACT
Amyloidosis consists of approximately 30 protein-folding disorders in which a specific soluble precursor protein aggregates to form the insoluble fibrils of amyloid. Insulin is the hypothesized precursor protein in localized cutaneous insulin-derived (AIns) amyloidosis. Amyloid deposition at insulin injection sites can interfere with absorption, leading to poor glucose control. Despite the increasing prevalence of diabetes mellitus and insulin use, there is a paucity of published cases of AIns amyloidosis and a lack of awareness of this condition among both dermatologists and general practitioners. We report 2 patients with insulin-dependent diabetes who developed hyperkeratotic nodules at insulin injection sites. Our cases complement the current data on iatrogenic amyloidosis and provide insight into this likely underreported phenomenon.
Subject(s)
Amyloidosis, Familial , Amyloidosis , Diabetes Mellitus , Amyloidosis/diagnosis , Humans , Insulin , SkinABSTRACT
Patch testing is widely used in evaluating suspected contact dermatitis. One major component of a quality patch test result is a dependable, predictable allergen supply. The allergen needs to be present at a sufficient concentration to elicit a reaction in an allergic patient. To better understand the stability of patch-test allergens, we completed a systematic review of the literature. We found that there is variability in stability among patch-test allergens and that although a few have been shown to be stable, many degrade when in storage. In most cases, expiration dates should be honored. In addition, allergen panels should be prepared as close to the time of patch test application as is possible.
