From Medscape Dermatology news
From Reuters Health Information
Screen for Scabies With Tape, Confirm With Dermoscopy: Study
NEW YORK (Reuters Health) Apr 13 - In resource-poor settings, the adhesive tape test is an ideal way to screen for scabies, say the authors of a new study. And dermoscopy - but not skin scraping - is good for diagnosis.
“If a trained dermatoscopist is not available, then the adhesive tape test is the method of choice,” they add.
Scabies, a mite infestation of the upper layer of the epidermis, affects up to half of children and 10% of adults in resource-poor rural and urban areas, said Dr. Birke Walter of Charite Universite Berlin and colleagues in the April issue of the Archives of Dermatology.
Microscopic examination of skin scrapings has long been the standard means of diagnoses. More recently it’s become possible to make an in vivo diagnosis using epiluminescence microscopy and dermoscopy.
To compare techniques in a resource-poor setting, Dr. Walter and colleagues recruited 125 Brazilian slum dwellers with a presumptive diagnosis of scabies.
Results were available for analysis on 113 individuals, 55% of whom were children. Forty-one people, or 36%, were diagnosed with scabies. Most had moderate infestations.
Sensitivity and specificity, respectively, were 0.83 and 0.46 for dermoscopy and 0.46 and 1.00 for skin scraping. For the tape test - which involves applying clear packing tape to a lesion, pulling it off, and examining it under a microscope within three hours - sensitivity and specificity were 0.68 and 1.00, respectively.
Dermoscopy was more sensitive for more severe disease, while disease severity didn’t influence the sensitivity of the adhesive tape test.