Food allergy (FA) affects approximately 6–8% of young children, with a peak prevalence at approximately one year of age. Tree nut and peanut allergies are among the main causes of anaphylaxis in the world. The gold standard for the diagnosis of FAs is the oral food challenge (OFC). Other diagnostic tests used in the clinical practice are skin prick tests (SPTs) and laboratory tests to measure out the presence of serum specific IgE (sIgE). In this narrative review, we collect the current evidence of the predictive value (PV) of SPTs and sIgE for the outcome of the OFCs. In literature, data are conflicting as to whether increasing sIgE concentration and wheal size in SPTs correlate with OFC outcomes. Most studies included in our review have shown that in vivo and in vitro tests may predict OFC outcomes with variable PV, but data are not conclusive; therefore, the OFC currently remains the gold standard for FA diagnosis.
