A pilot study of the usefulness and safety of a ready-to-use atopy patch test (Diallertest) versus a comparator (Finn Chamber) during cow's milk allergy in children.
BACKGROUND
Patch testing is used in the diagnosis of food allergy, especially during delayed manifestations.


OBJECTIVE
A ready-to-use atopy patch test (APT), the Diallertest, was compared with another APT device, the Finn Chamber, in pediatric cow's milk allergy.


METHODS
This prospective study involved 49 children (34.3 +/- 17 [mean +/- SD] months of age), with cow's milk allergy manifested by atopic dermatitis (10.2%), digestive manifestations (40.8%), or both (49%). All children underwent both APT techniques, with a reading 72 hours after application, followed by a milk elimination diet for 4 to 6 weeks and open cow's milk challenge.


RESULTS
A positive result was seen in 22 (44.8%) versus 13 (26.5%) patients with the ready-to-use and the comparator APTs, respectively. No side effects were recorded. Both techniques were concordant in 67.3% of patients. Of the total 41 open cow's milk challenges, 60.9% had positive results, with 8 patients lost to follow-up. The performances of the ready-to-use and comparator APTs were as follows: sensitivity, 76% (95% CI, 59.2% to 92.7%) versus 44% (95% CI, 24.5% to 63.4%; P = .02); specificity, 93.8% (95% CI, 81.9% to 100%) versus 93.8% (95% CI, 81.9% to 100%); positive predictive value, 95% (95% CI, 85.4% to 100%; 1 false-positive result) versus 91.7% (95% CI, 76% to 100%; 1 false-positive result); negative predictive value, 71.4% (95% CI, 52% to 90.7%; 6 false-negative results) versus 51.7% (95% CI, 33.5% to 69.8%; 14 false-negative results); and test accuracy, 82.9% (95% CI, 71.3% to 94.5%) versus 63.4% (95% CI, 48.6% to 78.1%; P = .05).


CONCLUSIONS
The ready-to-use APT exhibited a good sensitivity and specificity, with no side effects.
Kalach
Nicolas
N
Department of Pediatrics-Neonatology, Pediatric Gastroenterology and Nutrition Unit, Cochin-Saint Vincent de Paul Hospital, Paris, France. kalach.nicolas@ghicl.net
Soulaines
Pascale
P
de Boissieu
Delphine
D
Dupont
Christophe
C
D002648:Child; D002675:Child, Preschool; D005188:False Negative Reactions; D005189:False Positive Reactions; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007223:Infant; D016269:Milk Hypersensitivity / Q000175:diagnosis*; D010328:Patch Tests / Q000009:adverse effects / Q000379:methods*; D010865:Pilot Projects; D011446:Prospective Studies; D012680:Sensitivity and Specificity
D007073:Immunoglobulin E