Evaluation of allergic response using dynamic thermography

Abstract

Skin dynamic termography supplemented by a mathematical model is presented as an objective and sensitive indicator of the skin prick test result. Termographic measurements were performed simultaneously with routine skin prick tests. The IR images were acquired every 70 s up to 910 s after skin prick. In the model histamine is treated as the principal mediator of the allergic reaction. Histamine produces vasolidation and the engorged vessels are responsible for an increase in skin temperature. The model parameters were determined by fitting the analytical solutions to the spatio-temporal distributions of the differences between measured and baseline temperatures. The model reproduces experimental data very well (coefficient of determination = 0.805÷0.995). The method offers a set of parameters to describe separately skin allergic reaction and skin reactivity. The release of histamine after allergen injection is the best indicator of allergic response. The diagnostic parameter better correlates with the standard evaluation of a skin prick test (correlation coefficient = 0.98) than the result of the thermographic planimetric method based on temperature and heated area determination (0.81). The high sensitivity of the method allows for determination of the allergic response in patients with the reduced skin reactivity.

Thermographic imaging as alternative method in allergy diagnosis

“…The inter-subject variability of the parameter can be considered as a confirmation that the immediate allergic response is a highly individual-dependent process, but its value can reflect the skin reactivity. Previous studies have confirmed that histamine migration rate is also parameter responsible for the maximal radius of the heated region (correlation coefficient = 0.85) [12,13]. A comparison of the histamine migration rate with age of patients seems to be interesting (Fig.…”

“…The above rigorous analysis is not still satisfying because it does not allow to full explanation of about 10 % misinterpreted cases by SPT method. At this point very useful was the model analysis of thermograms which provides opportunity to determine the migration rate of the basic mediator of allergic reactionhistamine (v) [12,13]. Temporal acquisition of control histamine response allows estimating the migration rate of histamine (v) in the skin (average v = 0.013 ± 0.010 mm/ s, range: (0.007-0.041) mm/s).…”

“…Recently, a new thermographic (TH) method for the assessment of allergen-induced skin reactions was developed [12,13]. It was demonstrated that the thermographic measurements of forearm temperature distribution during SPT, supported by a mathematical model, offer a new quantification of allergen-induced skin reactions.…”

Calorimetry in Allergy Diagnostic

“…The strongest skin reaction observed after the Prick test is to the positive control. Its size varies between 10 and 30 mm [6]. The diameter of the holes in the template is 20 mm, which may not, in some cases, cover the full size of the reaction to a histamine solution.…”

“…For this reason, it is necessary to initially capture the skin areas and reposition the arm (Figure 3). Most studies do not analyze the initial skin temperature, although it is the starting point for the temperature change [6][7][8]. There were no statistically significant differences in skin temperatures prior to the test when subcutaneous main blood vessels were avoided [9].…”