We report a 54-year-old male, with a 5-year history of spreading asymptomatic generalized cutaneous telangiectases. The patient had no mucosal or nail involvement, no positive family history and no clinical evidence of systemic disease or bleeding diathesis. Histologically, the superficial small dermal blood vessels were dilated and showed thickened walls with hyaline perivascular material, staining as collagen. The vessel walls were PAS and colloidal iron stain positive, and immuno-histochemically lacked actin staining. Collagen IV, fibronectin and laminin antibodies showed the material deposited around the basement membrane zone. Ultrastructurally, the vessels were post-capillary venules (PCV) and showed marked collagen deposition around the basal lamina. There were many abnormally banded widely spaced fibres with 100-150 nm periodicity (Luse bodies), in addition to regular banded collagen. Pericytes were sparse and lacked intracytoplasmic filaments, and few veil or fibroblastic cells were seen embedded within the collagen. We believe this is a form of cutaneous microangiopathy not previously described, with distinct morphology and unique ultrastructural features. It may be due to a genetic defect with erroneous production of disorganized collagen in the cutaneous microvasculature. Dermatologists and Dermatopathologists should be aware of this unusual cutaneous vasculopathy.
To examine the development of expertise in dermatology, accuracy of diagnosis and response times of subjects at five levels of expertise were assessed. A total of 100 slides, 2 typical and 3 atypical slides from each of 20 common skin disorders, were presented to six subjects at each of the following levels: second-year preclinical medical students, final year medical students, residents in family medicine, general practitioners, and dermatologists. Accuracy of diagnosis rose from 21% for medical students to 87% for dermatologists. Correct diagnosis was associated with a decrease in response time with expertise, whereas errors were associated with a dramatic increase in response time, and was slower than correct response times at all levels, suggesting that errors do not result predominantly from carelessness or speed. Typical slides accounted for a constant proportion of diagnostic errors at all higher levels of expertise, and experts continued to make a significant proportion of errors on slides shown to be relatively easy for residents. The results are shown to be at variance with any model that equates expertise with the mastery of complex rules, but they are consistent with models of expertise that propose that expertise is equated with a rapid "pattern-recognition" process, and errors result from unintended confusion with previous similar examples.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.