Management of soya and peanut allergic patients taking oral isotretinoin

We read with interest the report from Alden et al (1) but have some reservations regarding their conclusions, especially as their protocol was driven by the reaction of their index patient. The index case developed a reaction after taking isotretinoin however the cause of this reaction is not clear. Firstly we question the relevance of the IgE to the Gly m4 protein. IgE to Gly m4 is not infrequent in the oral allergy syndrome due to cross reactivity to the Silver Birch pollen BetV1 protein that is found in people with spring time hayfever. This is a mild allergy with very rare extension to systemic anaphylaxis unless significant quantities are consumed, there is concomitant antacid/H2 antagonist/protein pump inhibitor therapy or a cofactor induced anaphylaxis.