I bruise so easily that I just have to walk by the corner of a table and I turn black and blue. I've recently started to play softball and now, of course, I'm covered in bruises. One of my teammates swears by arnica gel, and I've been using it mornings and evenings. Is it my imagination, or are these purplish marks disappearing faster?
The flowering plant from which Arnica products are made has had many names, including mountain snuff, leopard's bane and wolf's bane (not to be confused with a very different wolfbane popularized in the Harry Potter novels). But, since Professor Snape prepared the wolfbane potion to protect a colleague from becoming a werewolf rather than to heal his hairy bruises, perhaps there are greater mix-up implications for the local villagers than for you.
Arnica montana is member of the daisy family and is native to the mountains of Europe and Siberia. Its use in folk medicine for four centuries has made it a standard of the healing professions to this day. Currently, more than a hundred products containing this herbal ingredient are for sale in Germany. According to travel writer and botanist Nancy Allison, another name for the plant in the German mountain dialect translates to "stand up and go home," indicating either an effective pain reliever for frequent falls or attesting to the drunkenness of the local populace. An extract of the flowering heads of Arnica is made into creams, gels, tinctures and sprays. In addition, ever-increasing dilutions of the extract are in the basic armory of homeopathy, a field rife with controversy (there lies an ant hill I will gladly step over for now). The topical gels and creams available in American drugstores are most frequently marketed for swelling, bruising and pain relief.
Your many bruises form when capillaries under the skin are damaged and bleed, most often because of blunt trauma like a flying softball or an opponent's cleat. Often there is early swelling and soreness during which the characteristic blue-purple discoloration develops. Over time, the body breaks down the red blood cells, leaving a yellowish-green stain to remind you, for a while, anyway, of your poor fielding abilities. Arnica's longevity as an herbal remedy seems to be due to its ability to reduce initial swelling and to later increase blood circulation during the clean-up stage.
Although they may sound like a hex Draco Malfoy might use, sesquiterpene lactones are the substances found in Arnica that give the ointments their anti-inflammatory properties. A recent German study demonstrated that these active components will easily travel through the skin to stimulate circulation and decrease swelling. As exciting as that sounds, a major caution is that other compounds in the Arnica plant itself, as well as the essential oils, are quite toxic when taken internally. For that reason, never apply the cream to broken skin and no preparations of arnica should ever be ingested. An important exception to this rule is the highly diluted homeopathic remedies, which are completely safe under the watchful eye of your friendly naturopath.
Formal research into the efficacy of topical arnica creams and gels is scanty. One randomized, double-blinded, placebo controlled trial showed little positive result in preventing or healing bruising following laser treatment of facial lesions. On the other hand, quite encouraging results were found in a large Swiss study for increasing function and relieving the pain and stiffness of osteoarthritis. A thorough search of the medical literature reveals no further significant trials on external use. Certainly, more needs to be done, but it appears the only drawback to trying these products is the minor possibility of allergic skin reactions. Fairly infrequent side effects, itching and redness most commonly occur in those with hypersensitivity to the daisy family, which includes marigolds, chamomile, and in the Southern states, Bo and Luke Duke.
Although, I'm not convinced I can attribute your bruise disappearances to the gel, arnica does seem to have a long history of safe use as a healing accelerator. It's probably keeping the swelling in check whether or not it speeds clearing your skin. And, since you didn't mention that you play for the Hogwarts team, you probably don't have access to Madam Pomfrey's magical curative powers. So, it's just as well you play softball, as getting hit by a bludger while playing Quidditch leaves an awfully nasty bruise.