Stinging nettle, scientifically known as Urtica dioica, is a widely distributed plant. This common weed often elicits curiosity and concern due to its characteristic “sting.” While contact causes an uncomfortable reaction, it is not considered poisonous. Its effects are primarily irritating rather than life-threatening.
How Stinging Nettle Causes Irritation
The stinging sensation from nettle comes from specialized hollow hairs, called trichomes, that cover its leaves and stems. These delicate hairs act like tiny hypodermic needles; when brushed against, their fragile silica tips break off, allowing the remaining shaft to pierce the skin. This mechanical action is combined with the release of a cocktail of irritating chemicals stored within the hairs.
The chemicals injected into the skin include histamine, acetylcholine, serotonin, and formic acid. Histamine causes inflammation and pain, while acetylcholine and serotonin contribute to the stinging and burning sensation. Formic acid, though present, is not the primary irritant. Other compounds like leukotrienes and moroidin also contribute to the lasting effects. Skin contact results in raised bumps or hives surrounded by redness, with the affected area feeling an immediate stinging sensation followed by itching.
Stinging Nettle for Consumption
Despite its stinging properties, stinging nettle is safe and nutritious when prepared properly. Safe consumption requires neutralizing the stinging chemicals in its trichomes. Heat, through cooking, blanching, or drying, effectively disarms these irritants, making the plant safe to eat.
Raw nettle leaves should not be consumed due to irritation in the mouth and throat. Once cooked or dried, nettle can be incorporated into various dishes, much like spinach or kale. It has a long history of culinary use in soups, teas, and pesto, offering a slightly bitter, earthy flavor.
Managing Stinging Nettle Contact
If skin contact with stinging nettle occurs, immediate action can help reduce discomfort. Avoid rubbing or scratching the affected area for the first 10 minutes, as this can push chemicals and hairs deeper into the skin. After this period, wash the area thoroughly with soap and water to remove chemicals and embedded hairs. If soap and water are not immediately available, a clean, damp cloth can be used.
For ongoing relief, various home remedies can be applied. Cool compresses or ice packs can soothe pain and irritation, and a paste made from baking soda and water may help neutralize acidic compounds. Over-the-counter options like antihistamines can reduce itching and swelling, and hydrocortisone creams may alleviate inflammation. Natural remedies like crushed dock leaves or jewelweed are traditionally used for relief, though scientific evidence for their effectiveness varies. If a rash persists for more than 24 hours, worsens, or if severe symptoms like difficulty breathing, wheezing, or widespread swelling occur, immediate medical attention should be sought.