A 6-year-old patient presented with linear erythema and bullae on the face. The lesions developed after playing with plants the day before. The plant was identified as Euphorbia helioscopia L. (sun spurge). The sun spurge belongs to the Euphorbiaceae plant family. These plants produce a typical milky juice that causes toxic reactions following contact with skin and mucous membranes. In the literature several cases of toxic dermatitis caused by plants of the Euphorbiaeae family have been described. The most important differential diagnosis of these skin lesions is the bullous phototoxic dermatitis caused by psoralens. Plant-induced toxic dermatitis is of increasing importance in dermatology. The exact determination of the causative plants is a prerequisite for the diagnosis of phytodermatitis.