Predicting food challenge outcomes for baked milk: role of specific IgE and skin prick testing.
BACKGROUND
Cow's milk allergy is the most common food allergy in childhood. Many children with IgE-mediated cow's milk allergy may tolerate baked milk products, but few data exist on predictors of outcomes of baked milk challenges.


OBJECTIVE
To determine the relation of milk protein allergen specific IgE (sIgE) levels and skin prick test (SPT) wheal size with baked milk challenge outcomes.


METHODS
A retrospective medical record review was conducted of 35 baked milk challenges. SPT results, sIgE levels, demographic characteristics, and food challenge results were analyzed.


RESULTS
Thirty-five children underwent open challenges to baked milk and 29 (83%) passed. Of those who failed, 3 (50%) passed the initial clinic challenge but developed symptoms to ongoing exposure at home, days to months later. One child who ultimately failed at home required epinephrine. Compared with those who passed, children who failed were younger (median age, 8.9 and 3.7 years, respectively; P = .02). Children with a milk SPT wheal less than 12 mm were more than 90% likely to pass a baked milk challenge, and no child with a milk SPT wheal less than 7 mm failed a baked milk challenge. We were also able to establish more than 90% predictive values for passing baked milk challenges with a casein SPT wheal of 9 mm, a milk sIgE level of 1.0 kU/L, and a casein sIgE level of 0.9 kU/L.


CONCLUSIONS
Most children allergic to cow's milk tolerated baked milk. Milk protein SPT wheal may be more reliable than sIgE level in predicting outcomes of baked milk challenges. It is important to be aware of the possibility of late reactions to ongoing baked milk exposure.
Boston Children's Hospital, Boston, Massachusetts 02115, USA.
Lisa M
LM
Bartnikas
William J
WJ
Sheehan
Elaine B
EB
Hoffman
Perdita
P
Permaul
Anahita F
AF
Dioun
James
J
Friedlander
Sachin N
SN
Baxi
Lynda C
LC
Schneider
Wanda
W
Phipatanakul
D000918:Antibody Specificity; D003296:Cooking; D006358:Hot Temperature; D006801:Humans; D007073:Immunoglobulin E / Q000096:biosynthesis / Q000502:physiology*; D016269:Milk Hypersensitivity / Q000175:diagnosis* / Q000276:immunology*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012882:Skin Tests; D016896:Treatment Outcome
D007073:Immunoglobulin E