page_title: Urtica dioica
section_title: Nettle sting mechanism and treatment
hierarchical_section_title: Urtica dioica / Nettle sting mechanism and treatment
caption_attribution_description: Urtica dioica
context_page_description: Urtica dioica, often known as common nettle, stinging nettle or nettle leaf, or just a nettle or stinger, is a herbaceous perennial flowering plant in the family Urticaceae. Originally native to Europe, much of temperate Asia and western North Africa, it is now found worldwide, including New Zealand and North America. The species is divided into six subspecies, five of which have many hollow stinging hairs called trichomes on the leaves and stems, which act like hypodermic needles, injecting histamine and other chemicals that produce a stinging sensation upon contact. The plant has a long history of use as a source for traditional medicine, food, tea, and textile raw material in ancient societies.
context_section_description: Urtica dioica produces its inflammatory effect on skin (stinging, burning sensation often called "contact urticaria") both by impaling the skin via spicules – causing mechanical irritation – and by biochemical irritants, such as histamine, serotonin, and acetylcholine, among other chemicals. Anti-itch drugs, usually in the form of creams containing antihistamines or hydrocortisone, may provide relief from nettle dermatitis. The term, contact urticaria, has a wider use in dermatology, involving dermatitis caused by various skin irritants and pathogens. Dock leaves, which often grow in similar habitats, are regarded as a folk remedy to counteract the sting of a nettle, although there is no evidence of any chemical effect. It may be that the act of rubbing a dock leaf against a nettle sting acts as a distracting counterstimulation, or that belief in the dock's effect provides a placebo effect.
caption: U. dioica  close-up of the defensive hairs
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