SPT predictive values for the outcome of cashew challenges in children.
McWilliam, V., Peters, R. L., Allen, K. J., Dharmage, S. C., Ponsonby, A. L., Tang, M. L., … & Taranto, M.
BACKGROUND: Cashew is a common cause of tree nut allergy in children. To date there have been few studies of diagnostic tests for cashew allergy, and positive predictive values (PPVs) for cashew as well as other tree nuts are largely extrapolated from studies of peanut allergy. How relevant these cut-offs are for cashew has not been formally explored. OBJECTIVE: We aimed to establish skin prick test (SPT) wheal sizes that correlated to 95% PPV for a positive food challenge for cashew. METHODS: We included all cashew oral food challenges (OFC) conducted as part of the HealthNuts (n=108, age 4-6 years) and SchoolNuts (n=37, age 10-14 years) studies, both recruited from the community (Population cohort). A second cohort of all cashew OFCs conducted at the Royal Children’s Hospital (RCH) allergy centre (n=343) (2011-2016) and a private allergy clinic based at RCH (n=43) was included via electronic medical record review (Clinic cohort). 95% PPV for cashew SPT was calculated for both cohorts. RESULTS: Among the population cohort (n=145), 62% of cashew OFC were positive compared to 20% of the clinic cohort (n=386). The SPT cut-off for 95% PPV derived from the population cohort was 10mm (95%CI 7.5-12.0). For the clinic cohort the 95% PPV was 14mm (95%CI 9.5-unknown). A SPT wheal size of 8mm had a PPV of 89% (95%CI 79-95) in the population cohort and 62% (95%CI 45-78) in the clinic cohort. CONCLUSION: A higher SPT wheal size may be more appropriate than the commonly used 8mm cut-off to guide clinical decisions around when to perform OFC for cashew.
BECOME A SUBSCRIBER
Sign up to receive our newsletter with recipe ideas healthy tips and more
To provide the best experiences, we use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us to process data such as browsing behaviour or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
The technical storage or access that is used exclusively for statistical purposes.The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.