TY - JOUR
T1 - The lancet weight determines wheal diameter in response to skin prick testing with histamine
AU - Andersen, Hjalte Holm
AU - Lundgaard, Anna Charlotte
AU - Sohrt Petersen, Anne
AU - Hauberg, Lise Eun
AU - Sharma, Neha
AU - Damkjær Hansen, Sofie
AU - Elberling, Jesper
AU - Arendt-Nielsen, Lars
PY - 2016
Y1 - 2016
N2 - BACKGROUND: Skin prick test (SPT) is a common test for diagnosing immunoglobulin E-mediated allergies. In clinical routine, technicalities, human errors or patient-related biases, occasionally results in suboptimal diagnosis of sensitization.OBJECTIVE: Although not previously assessed qualitatively, lancet weight is hypothesized to be important when performing SPT to minimize the frequency of false positives, false negatives, and unwanted discomfort.METHODS: Accurate weight-controlled SPT was performed on the volar forearms and backs of 20 healthy subjects. Four predetermined lancet weights were applied (25 g, 85 g, 135 g and 265 g) using two positive control histamine solutions (1 mg/mL and 10 mg/mL) and one negative control (saline). A total of 400 SPTs were conducted. The outcome parameters were: wheal size, neurogenic inflammation (measured by superficial blood perfusion), frequency of bleeding, and the lancet provoked pain response.RESULTS: The mean wheal diameter increased significantly as higher weights were applied to the SPT lancet, e.g. from 3.2 ± 0.28 mm at 25 g to 5.4 ± 1.7 mm at 265 g (p<0.01). Similarly, the frequency of bleeding, the provoked pain, and the neurogenic inflammatory response increased significantly. At 265 g saline evoked two wheal responses (/160 pricks) below 3 mm.CONCLUSION AND CLINICAL RELEVANCE: The applied weight of the lancet during the SPT-procedure is an important factor. Higher lancet weights precipitate significantly larger wheal reactions with potential diagnostic implications. This warrants additional research of the optimal lancet weight in relation to SPT-guidelines to improve the specificity and sensitivity of the procedure.
AB - BACKGROUND: Skin prick test (SPT) is a common test for diagnosing immunoglobulin E-mediated allergies. In clinical routine, technicalities, human errors or patient-related biases, occasionally results in suboptimal diagnosis of sensitization.OBJECTIVE: Although not previously assessed qualitatively, lancet weight is hypothesized to be important when performing SPT to minimize the frequency of false positives, false negatives, and unwanted discomfort.METHODS: Accurate weight-controlled SPT was performed on the volar forearms and backs of 20 healthy subjects. Four predetermined lancet weights were applied (25 g, 85 g, 135 g and 265 g) using two positive control histamine solutions (1 mg/mL and 10 mg/mL) and one negative control (saline). A total of 400 SPTs were conducted. The outcome parameters were: wheal size, neurogenic inflammation (measured by superficial blood perfusion), frequency of bleeding, and the lancet provoked pain response.RESULTS: The mean wheal diameter increased significantly as higher weights were applied to the SPT lancet, e.g. from 3.2 ± 0.28 mm at 25 g to 5.4 ± 1.7 mm at 265 g (p<0.01). Similarly, the frequency of bleeding, the provoked pain, and the neurogenic inflammatory response increased significantly. At 265 g saline evoked two wheal responses (/160 pricks) below 3 mm.CONCLUSION AND CLINICAL RELEVANCE: The applied weight of the lancet during the SPT-procedure is an important factor. Higher lancet weights precipitate significantly larger wheal reactions with potential diagnostic implications. This warrants additional research of the optimal lancet weight in relation to SPT-guidelines to improve the specificity and sensitivity of the procedure.
KW - Journal Article
U2 - 10.1371/journal.pone.0156211
DO - 10.1371/journal.pone.0156211
M3 - Journal article
C2 - 27213613
SN - 1932-6203
VL - 11
JO - P L o S One
JF - P L o S One
IS - 5
M1 - e0156211
ER -