Comparison 1. Tartrazine challenge versus Placebo.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 PC20 ‐ Histamine (mg/ml)	1	18	Mean Difference (IV, Fixed, 95% CI)	‐0.87 [‐6.30, 4.56]
2 PEFR (litres/min)	1	18	Mean Difference (IV, Fixed, 95% CI)	‐7.0 [‐103.37, 89.37]
4 Adverse Events	1	554	Risk Ratio (M‐H, Fixed, 95% CI)	1.0 [0.33, 3.06]