[Double-blind randomized trial of the effect of Bidro on hay fever in children]

The natural product royal jelly (trade name Bidro) is widely used for the treatment and prevention of allergic symptoms. Several case reports suggest marked clinical benefits. Our aim was to assess whether treatment with royal jelly modifies the development of allergic hay fever symptoms in children with pollen allergy.

Eighty children aged 5-16 years with hay fever symptoms due to birch, grass and/or mugwort participated in a placebo-controlled, double-blind, randomized, controlled trial. Treatment with royal jelly or placebo was administered three to six months before and throughout the pollen season.

The primary outcome was the occurrence of symptoms of rhinitis and conjunctivitis in the pollen season. A secondary outcome was symptom severity, as measured by symptom score, by visual analog scale (VAS) and by the need for additional hay fever treatment. Sixty-four children completed the study; 34 of them had been treated with royal jelly and 30 with placebo. All of the patients in both groups developed hay fever symptoms during in the pollen season. The severity of hay fever symptoms was similar in the two groups (VAS = 1.6 in the placebo group and 1.4 in the royal jelly group; the mean number of combined daily nasal symptoms was 2.83 in the placebo group and 2.82 in the royal jelly group). The need for additional hay fever treatment was similar in the two groups.

We conclude that royal jelly has no effect on the occurrence of hay fever in the pollen season, nor does it modify the severity of hay fever symptoms.