[Use of thermography methods for evaluating skin prick tests. I. Background temperature of area where skin prick tests are performed. Optimal color scale of temperature differences registered by liquid crystals and conditions of their use].

The aim of the study was to estimate the value in visualization of temperature gradients in assessing results of skin prick tests. The study group consisted of 10 patients suspected of having allergic diseases in whom skin prick tests were carried out. They were performed typically using the Bencard allergens kits. A positive control was performed using different solutions of histamine (10 mg/ml, 1 mg/ml, 0.1 mg/ml). The traditional method comprising of measurement of erythema, and whed was compared with visual thermography and open liquid crystal themography. The background temperature of typical areas chosen for skin prick tests were compared under condition of thermographic evaluation. The skin of the upper region of the back was chosen for uniform temperature background. Basing on the analysis of the background temperature and in areas of high reaction to histamine and allergens the temperature and in areas of high reaction to histamine and allergens the temperature gradient was calculated to be 2.2 degrees--2.5 degrees C. In order to visualize this gradient in composition of liquid crystals was made of a working range of 34.3 degrees--36.3 degrees C. Criteria for a correct thermographic evaluation of skin prick tests were established after studying the effect of manipulation of the area examined, local lowering of the temperature, use of cold solutions of allergens. Further studies are planned in order to assess the practical use of this thermographic analytical method.