Stinging nettle dermatitis.

The stinging nettle (Urtica dioica) is a common weed that can cause a wide range of cutaneous reactions. Contact with the hairs or spines on the stems and leaves of the stinging nettle causes the release of several biologically active substances. The released chemicals act to cause itching, dermatitis, and urticaria within moments of contact. Extracts from the stinging nettle may provide therapeutic value for some inflammatory medical conditions. There is no standard treatment for stinging nettle dermatitis.