Is oral isotretinoin treatment contraindicated for patients with known peanut allergies?

Introduction

The criterion standard for the treatment of severe nodular cystic acne, oral isotretinoin, contains soybean oil, which is contraindicated in patients with a soy immunoglobulin E–mediated allergy. Given the possibility of soy–peanut cross-reactivity, isotretinoin leaflets in the United Kingdom and Australia indicate that the drug is contraindicated in patients who have allergies to peanut or soy.1, 2, 3 This has been discussed in European dermatologic literature. We recently had a patient who was initially denied access to isotretinoin because of his peanut allergy, and we briefly report our findings in the American dermatologic literature.

Case report

A 21-year-old man presented for severe acne vulgaris. He was being treated with oral minocycline with minimal improvement and was prescribed oral isotretinoin. The pharmacist declined to fill the prescription given the patient's medical history of a known peanut allergy. The patient was referred to an allergist for evaluation. While he was verified by skin prick testing to have a reaction to peanuts, he was not sensitive to soy. He had not been avoiding soy in his diet and had not had a reaction to it. His soybean immunoglobulin E level was negative. The patient has since initiated treatment and exhibited a notable clinical improvement with no adverse allergic events.

Discussion

Each generic isotretinoin capsule sold in the United States contains hydrogenated soybean oil or soybean oil; the package inserts state that the drug is contraindicated in patients with hypersensitivities to this medication or to any of its components. No explicit mention of peanut allergies is made. Individuals with peanut allergy are not advised to avoid soy unless they are also known to possess immunoglobulin E–mediated allergies to soy as well.⁴ In addition, because allergies to peanut and soy are related to the protein content, not the oil, properly purified oil possesses minimal risks.

Case reports from the literature have demonstrated successful isotretinoin treatment in patients with known peanut allergies.⁵ These studies, and our case, indicate that a positive peanut allergy should not serve as a contraindication to isotretinoin.