Avaliação objetiva de teste cutâneo de leitura imediata (skin prick test) através de métodos planimétricos por imagem, e termometria da reação

• Ano de defesa: 2020
• Autor(a) principal: Almeida, Ana Laura Mendes
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Teste de puntura; Termometria da reação; Puntura; Área da pápula; Skin prick test; Puncture test; Reaction thermometry; Papule area
• Link de acesso: http://hdl.handle.net/11449/192466

The skin prick test is used to diagnose patients' sensitization to antigens through a mediated IgE response. It is a practical and quick exam, but its diagnosis depends of instruments for measuring the allergic response and observer's interpretation. The conventional method for inferring about the allergic reaction is performed from the dimensions of the papules, which are measured using a ruler or a caliper. To make this diagnosis less dependent of human interpretation, the present study proposes two alternative methods to infer about the allergic reaction: computational analysis of the papule area and a study of the temperature variation of the patient's skin in the puncture region. For this purpose, the histamine prick test was performed on 13 patients random selected. The areas were determined by the conventional method using the dimensions of the papules measured with a digital caliper 30 minutes after the puncture. The papule areas were also determined by a Python algorithm using photos of the puncture region obtained by a smartphone. A variable named circularity deviation was also determined for each analyzed papule. The temperature variation was monitored using an infrared temperature sensor, which collected temperature data for 30 minutes. The results shown that the areas considered as real papule areas (computationally determined) differed significantly from the areas determined by the conventional method (p-value = 0.0005674), especially when the papules' contours were irregular due the pseudopod formation. Temperature monitoring revealed that there was a consistent increase in the temperature in the first minutes after the puncture, followed by stabilization, so that the data could be adjusted by a logistic equation (R2 = 0.96). This adjustment showed that the optimal time to measure the temperature is 10 minutes after the puncture, when occurs the temperature stabilization. The results also shown that this temperature stabilization has a significant correlation with papule area (p-value = 0.005585). Thus, we concluded that the proposed computational method is more accurate to infer the papule area and the temperature can be used as an alternative method to infer about the allergic reaction. Therefore, these two methods can contribute to the diagnosis of the allergic reaction and to evaluate drugs that aim to reduce the intensity of the IgE-mediated response.