Most cases of stinging nettle rash can be treated at home by washing the area, using an over-the-counter antihistamine, applying a cold compress, avoiding hot water, applying a baking soda and water paste and applying calamine lotion, according to Scott & White Healthcare. Most of these treatment options are not necessary for more mild cases, and the patient will likely notice immediate relief once the area has been properly cleaned.
It is possible for the reaction to stinging nettle to be more severe, such as if the patient has a specific allergic reaction to the plant. If the patient has difficulty breathing or has a serious reaction involving hives or swelling, he or she should seek emergency medical help immediately, notes Scott & White Healthcare.
There are possible benefits to using stinging nettle to treat osteoarthritis, according to WebMD. There is some evidence that taking a stinging nettle supplement or applying stinging nettle to the skin in areas where the patient is experiencing pain from osteoarthritis can be beneficial. This regimen could even eliminate or reduce the need for pain medications in osteoarthritis patients. Possible side effects include stomach discomfort and sweating, and patients who apply the plant to the skin are at risk for rashes.