Facial thermography is a sensitive and specific method for assessing food challenge outcome
- 15 June 2007
- Vol. 62 (7), 744-749
- https://doi.org/10.1111/j.1398-9995.2007.01363.x
Abstract
Oral challenge is widely used for diagnosing food allergy but variable interpretation of subjective symptoms may cause error. Facial thermography was evaluated as a novel, objective and sensitive indicator of challenge outcome. A total of 24 children with a history of egg allergy underwent oral challenge, which were scored positive when objective symptoms occurred or negative after all doses were consumed without reaction. Facial temperatures were recorded at baseline and 10-min intervals. The difference between mean and baseline temperature (DeltaT), maximum DeltaT during challenge (DeltaT(max)) and area under curve of DeltaT against time (DeltaTAUC) were calculated for predefined nasal, oral and forehead areas, and related to objective challenge outcome. There were 13 positive and 11 negative challenges. Median nasal DeltaTAUC and DeltaT(max) were greater in positive compared with negative challenges (231- and 5-fold, respectively; P < 0.05). In positive challenges, nasal temperatures showed an early transient rise at 20 min, preceding objective symptoms at median 67 min. There was a sustained temperature increase from 60 min, which was reduced by antihistamines. A cut-off for nasal DeltaT(max) of 0.8 degrees C occurring within 20 min of the start of the challenge predicted outcome with 91% sensitivity (positive predictive value [PPV] 100%) and 100% specificity (negative predictive value [NPV] 93%). Subjective symptoms occurred in four of 13 positive and three of 11 negative challenges. Facial thermography consistently detects a significant early rise in nasal temperature during positive compared with negative food challenges, which is evident before objective symptoms occur. Thermography may therefore provide a sensitive method to determine outcome of food challenges and investigate the pathophysiology of food allergic reactions.Keywords
This publication has 17 references indexed in Scilit:
- Does severity of low‐dose, double‐blind, placebo‐controlled food challenges reflect severity of allergic reactions to peanut in the community?Clinical and Experimental Allergy, 2005
- IgE mediated food allergy: when is food challenge needed?Archives of Disease in Childhood, 2005
- Standardization of food challenges in patients with immediate reactions to foods – position paper from the European Academy of Allergology and Clinical ImmunologyAllergy, 2004
- Interpretation of tests for nut allergy in one thousand patients, in relation to allergy or toleranceClinical and Experimental Allergy, 2003
- The distribution of individual threshold doses eliciting allergic reactions in a population with peanut allergyJournal of Allergy and Clinical Immunology, 2002
- Utility of food-specific IgE concentrations in predicting symptomatic food allergyJournal of Allergy and Clinical Immunology, 2001
- Food allergy–getting more out of your skin prick testsClinical and Experimental Allergy, 2000
- Specificity of allergen skin testing in predicting positive open food challenges to milk, egg and peanut in childrenClinical and Experimental Allergy, 2000
- An evaluation of the sensitivity of subjects with peanut allergy to very low doses of peanut protein: A randomized, double-blind, placebo-controlled food challenge studyJournal of Allergy and Clinical Immunology, 1997
- Use of thermography in clinical allergyJournal of Allergy and Clinical Immunology, 1972