Pain assessment in autism: updating the ethical and methodological challenges through a state-of-the-art review

Sensory features of autism include hypo- or hyper-reactivity to pain; however, previous studies on pain in autism lead to conflicting results. Here, we present the state of the art and the methodological challenges concerning pain perception in autism, focusing on studies that used standardized protocol as Quantitative Sensory Testing (QST) to measure perception. Despite there are still scant evidences found with the use of QST, they have challenged the presumed hyposensitivity to pain in autisms, which emerged from parents' reports. Both, peripheral and central mechanisms, have been found involved in typical features of perception in autism. Nonetheless, evidences with controlled protocols are still scarce, and even scarcer are studies focused on children. Overall, complex ethical challenges have to be overcome in order to collect subjective and objective measures from autistic children. With heterogeneous neurodevelopmental features, or intellectual disability, novel or modified protocols are needed.

Automated summary

The sensory features of autism include hypo- or hyper-reactivity to pain, although previous studies on pain in autism have yielded conflicting results. This article discusses the current state of knowledge and methodological challenges regarding pain perception in autism, with a focus on studies that used standardized protocols such as Quantitative Sensory Testing (QST) to measure perception. The use of QST has challenged the assumption of hypo-sensitivity to pain in autism, which was based on parents' reports, as there is limited evidence supporting it. Both peripheral and central mechanisms have been found to be involved in the typical features of pain perception in autism. However, there is a scarcity of studies with controlled protocols, particularly in children. Collecting subjective and objective measures from autistic children presents complex ethical challenges that need to be addressed. Given the heterogeneity of neurodevelopmental features and intellectual disability in autism, novel or modified protocols are necessary for future research.