Walnut Tree Mulch and Nut Allergy Risks

A school nurse asks if black walnut mulch in a play area could trigger severe skin itching in a 4-year-old with peanut, tree nut, and egg allergies.

Assessment

With severe nut allergies, walnut mulch poses a legitimate risk. Juglone and other compounds in walnut tissue can cause contact reactions in sensitive individuals. Research supports caution—see walnut allergy references.

Recommendation

Children with severe nut allergies should avoid direct contact with walnut mulch. Alternative mulch materials (pine bark, cedar, rubber) eliminate this exposure pathway.