Parental Reports on Pain Reactivity and Pain Expression In Children with Autism Spectrum Disorder

Background:

Clinical observations and anecdotal reports suggest that children with autism spectrum disorder (ASD) have abnormal behavioral responses to pain such as the absence of withdrawal reflexes or protecting a broken limb. Presently, few reports have systematically assessed pain reactivity and pain expression in children with ASD, and have reported discrepant results. Improved information concerning the extent of children’s pain reactivity levels and how they express their pain would aid in improving pain management in this population.

Objectives:

To objectively assess pain reactivity and expressiveness for children with ASD.

Methods:

A semi-structured interview was conducted with 47 parents (45 mothers, 2 fathers; age=44 ± 12 yrs) of 53 children with ASD (48 boys, 5 girls; mean age=10 ± 5 yrs; range=3-18 yrs). Parents were asked to describe their child’s physical and emotional reaction to pain and whether their child had low, normal or high pain reactivity. Parents completed the Non-Communicating Child’s Pain Checklist to rate how their children expressed pain (vocalization, socialization, facial expressions, changes in activities, physiological symptoms, and differences in eating and sleeping habits). In the instance where parents had multiple children with ASD, they rated pain reactivity and pain expression separately for each child.

Results:

Children differed in pain reactivity: 55% of the children had low pain reactivity, 19% had high pain reactivity and 23% were within the normal range. Pain reactivity of the children and adolescents did not vary by age (F=0.92; p=0.6) when assessing the data using a univariate general linear model. Additionally, no age differences were seen when removing the data from the girls from the analysis. Scores on the Non-Communicating Child’s Pain Checklist indicated that parents assessed children’s pain by evaluating behavioural cues, especially body movements (mean = 8.2; sd=3.7, p<0.03) and facial expressions (mean=6.8; sd=4.3; p<0.03) more so in comparison to the other five domains on the questionnaire, assessed using a one-way ANOVA. We subsequently assessed whether pain reactivity in the children would influence the means by which they express pain. Parents assessed pain comparatively across six of the seven domains of pain expression among the three pain reactivity groups. However, parents rated that they used vocalizations to identify pain in their children with high pain reactivity (mean 7.3; sd=2.5) significantly more so in comparison to children who were rated as having normal (mean=5.75, sd=2.9) or low pain reactivity (mean=4.4, sd=2.8; F=4.09; p=0.02). 

Conclusions:

Pain reactivity in children and adolescents with ASD varies considerably from low to high levels, independent of children’s age or sex. Although children with high pain reactivity tend to express pain more vocally in addition to expressing pain through their body movements and facial expressions, parents should assess both overt and subtle signs of distress when assessing pain in children with ASD. Future research will evaluate how pain reactivity and pain expression are related to pain processing in children with ASD.