Premium
Precise area determination of skin‐prick tests: validation of a scanning device and software for a personal computer
Author(s) -
POULSEN L. K.,
LIISBERG C.,
BINDSLEVJENSEN C.,
MALLING H.J.
Publication year - 1993
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1111/j.1365-2222.1993.tb02485.x
Subject(s) - scanner , biomedical engineering , personal computer , software , skin thickness , computer software , circumference , nuclear medicine , computer science , mathematics , medicine , artificial intelligence , computer hardware , geometry , computational science , programming language
Summary When skin‐prick tests (SPTs) are used quantitatively, the circumference of the weal and/ or the flare is outlined using a felt tip pen, and transferred to paper by adhesive tape. The aim of the study was to develop and validate a procedure, objectively and precisely determining these areas after transfer to paper. A system was developed enabling the drawing of the area of weal or flare to be read by a hand‐held scanner and calculated on a personal computer. Areas in the 5‐500 mm 2 range could be determined with day‐to‐day and interoperator coefficients of variation (CVs) of 3.3% and 1.1%, respectively. Accuracy was determined in two ways: by correlation to cutting/weighing of four times enlarged SPT areas ( r 2 = 0.0, P < 0.0) and by measuring standardized areas (deviations less than intra‐assay CV, i.e. 1‐2%). For comparison, CVs of alternative methods were also determined: eight different areas (9‐76 mm 2 ) were evaluated in quadruplicate using the SPT‐scanner (CV=1.1%), by cutting/weighing of paper (CV = 2.2%), by digitizing (CV = 4.4%) or by measuring longest and orthogonal diameters (CV= 13.13%). In conclusion, the scanning device and software provides an objective and reproducible procedure for rapid determination of SPT areas. When areas are determined by scanning, digitizing or cutting/weighing the variations in area determination becomes negligible compared to the variations of the entire skin test procedure.