Figure 4From: Positive serum specific IgE has a short half-life in patients with penicillin allergy and reversal does not always indicate toleranceDistribution of the estimated serum half-life (T½) of specific IgE to penicillins. No differences were seen between the four penicillins. ∞: Symbol of infinity, including the 3 cases with stable and increasing IgE-values over time. Specific IgE to penicillins includes benzylpenicillin, phenoxymethyl penicillin, ampicillin and amoxicillin.Back to article page