Conjunctival provocation test in diagnosis of peanut allergy in children.
BACKGROUND
Peanut allergy frequently causes severe allergic reactions. Diagnosis includes detection of IgE to peanuts in serum or by skin prick tests. While children may have allergic sensitization without having clinical peanut allergy, oral peanut challenge is often required for accurate diagnosis. The conjunctival provocation test is used for diagnosis and evaluation of treatment effect in inhalant allergies, but it has not been evaluated as a tool for diagnosing peanut allergy.


OBJECTIVE
To investigate whether the conjunctival provocation tests may be feasible, accurate and safe in diagnosing clinically relevant peanut allergy in patients with suspected peanut allergy.


METHODS
This cross-sectional case-control study in children with clinical or laboratory suspected peanut allergy included 102 children recruited from the regional paediatric departments and specialist practices during one year from April 2011. A peanut-tolerant control group of 28 children of similar age was recruited locally. A double-blind placebo-controlled conjunctival provocation test with peanut extract was performed in all children, while oral peanut provocation was performed as double-blind placebo-controlled challenge in children with suspected peanut allergy and as an open challenge in the control children.


RESULTS
All 81 children with a positive double-blind placebo-controlled oral food challenge (OFC) also had a positive conjunctival provocation test. None of the children with negative conjunctival provocation test had a positive OFC. The sensitivity and the specificity of the conjunctival provocation test were 0.96 and 0.83, respectively. No children had severe adverse reaction caused by the conjunctival provocation test, whereas 23 children suffered an anaphylactic reaction to the OFC.


CONCLUSIONS
Conjunctival allergen challenge appears to be feasible, accurate and safe in diagnosing children referred for suspected peanut allergy.
Department of Paediatrics, Oslo University Hospital, Oslo, Norway.
H
http://orcid.org/0000-0001-8271-9091
H
Lindvik
Department of Paediatrics, Oslo University Hospital, Oslo, Norway.|Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
K C
KC
Lødrup Carlsen
Department of Paediatrics, Oslo University Hospital, Oslo, Norway.
P
P
Mowinckel
Department of Ophthalmology, Oslo University Hospital, Oslo, Norway.
J
J
Navaratnam
ImmunoDiagnostic Division, Thermo Fisher Scientific, Uppsala, Sweden.|Department of Women' s and Children's Health, Uppsala University, Uppsala, Sweden.
M P
MP
Borres
Department of Paediatrics, Oslo University Hospital, Oslo, Norway.|Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
K-H
KH
Carlsen
D000293:Adolescent; D010367:Arachis / Q000009:adverse effects; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003228:Conjunctiva / Q000187:drug effects*; D003430:Cross-Sectional Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007159:Immunologic Tests / Q000379:methods*; D008297:Male; D021183:Peanut Hypersensitivity / Q000175:diagnosis*; D010936:Plant Extracts / Q000009:adverse effects*
D010936:Plant Extracts
anaphylaxis; conjunctival provocation test; food allergy; oral food challenge test; paediatrics