cowhage

Cowhage refers to Mucuna pruriens, a tropical climbing legume in the pea family. The name also denotes the dense, hair-like covering on the plant’s seed pods, which release a potent itch-inducing substance when disturbed. The hairs contain mucunain, a protease that is released on contact and provokes a strong pruritus that can last for hours and spread across the skin.

Description and symptoms. Mucuna pruriens is a perennial vine with compound leaves, twining stems, and pods densely covered in fine, irritating hairs. When the hairs are damaged, mucunain and other compounds irritate sensory nerve endings, leading to intense itching, sometimes accompanied by redness and swelling. The dermatitis can be severe if contact is prolonged or repeated.

Distribution and uses. Native to tropical Africa and parts of Asia, cowhage has become widespread in tropical regions as a forage legume and cover crop, valued for soil enrichment and erosion control. The seeds of some Mucuna pruriens varieties are high in L-DOPA (levodopa) and have been explored for medicinal use in Parkinson’s disease, though raw seeds and unprocessed plant material can be toxic and are not suitable for general consumption. The plant is also studied for its potential as green manure and in agroforestry systems.

Research and safety. In dermatology and neuroscience, cowhage spicules are used in controlled itch experiments to study itch pathways and receptor mechanisms. Handling cowhage can cause dermatitis, so gloves and care are advised when working with the plant to prevent skin and mucosal irritation.