We describe a young woman with urticarial contact dermatitis. She stated that she had itchy hand eczema that rapidly worsened after contact with tofu. She became nauseated when she consumed tofu or other foods containing soybean components. Prick and patch tests showed a positive skin reaction to soybean, and serological investigation revealed the presence of an antibody against the soybean allergenic protein components Gly m Bd 30K and Kunitz soybean trypsin inhibitor. The findings were consistent with those of urticarial contact dermatitis, which is assumed to be mediated by IgE, but the skin lesions show eczematous features.
Ikeda I, Ogawa T, Ono T. Tofu-Induced Urticarial Contact Dermatitis. Arch Dermatol. 2000;136(1):127-128. doi: