The term, contact urticaria, has a wider use in dermatology, involving dermatitis caused by various skin irritants and pathogens.Docks, especially the broad-leaf dock (Rumex obtusifolius) often grow in similar environments to stinging nettles and 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 docks effect provides a placebo effect. Uses
Culinary
U. dioica has a flavour similar to spinach when cooked. Young plants were harvested by Native Americans and used as a cooked plant in spring when other food plants were scarce. Soaking stinging nettles in water or cooking removes the stinging chemicals from the plant, which allows them to be handled and eaten without injury. After the stinging nettle enters its flowering and seed-setting stages, the leaves develop gritty particles called cystoliths, which can irritate the kidneys and urinary tract. : 106–107   Cystoliths are made of calcium carbonate, and will not dissolve when boiled. Leaves harvested post-flowering must have their cystoliths broken down by acid, as in the fermentation process. In its peak season, nettle contains up to 25% protein, dry weight, which is high for a leafy green vegetable. The leaves are also dried and may then be used to make a herbal tea, as can also be done with the nettles flowers. Nettles can be used in a variety of recipes, such as polenta, pesto, and purée.
Nettle soup is a common use of the plant, particularly in Northern and Eastern Europe. Nettles are sometimes used in cheesemaking, such as for Cornish Yarg and as a flavouring in varieties of Gouda.Nettles are used in Montenegro, Serbia and Bosnia and Hercegovina as part of the dough filling for the börek pastry. The top baby leaves are selected and simmered, and then mixed with other ingredients such as herbs and rice, before being used as a filling between dough layers. Similarly, in Greece the tender leaves are often used, after simmering, as a filling for hortopita, which is similar to spanakopita, but with wild greens rather than spinach for filling.Young nettles can also be used to make an alcoholic drink. Competitive eating
In the UK, an annual World Nettle Eating Championship draws thousands of people to Dorset, where competitors attempt to eat as much of the raw plant as possible. Competitors are given 60 cm (24 in) stalks of the plant, from which they strip the leaves and eat them. Whoever strips and eats the most stinging nettle leaves in a fixed time is the winner. The competition dates back to 1986, when two neighbouring farmers attempted to settle a dispute about which had the worst infestation of nettles, and one of them said, "Ill eat any nettle of yours thats longer than mine." Traditional medicine
As Old English stiðe, nettle is one of the nine plants invoked in the pagan Anglo-Saxon Nine Herbs Charm, recorded in 10th century traditional medicine.