Henna has strong antifungal, anti-inflammatory, analgesic, antibacterial, antiparasitic and antiperspirant properties. Recent studies have demonstrated the antibacterial effects of henna leaves against E. coli. Laboratory tests have demonstrated that, in comparison to alcoholic extract of henna, its aqueous extract has stronger antifungal effects against Malassezia fungus. Also, the substances isolated from hydroalcoholic extract of henna leaves have antioxidant and oxygen radical scavenging properties. Based on the results of studies carried out on laboratory animals, henna extract causes wound contraction, reduction in epithelialization time and considerable increase in the weight of granulation tissue; therefore, use of henna extract is suggested for wound healing.
In Iran, henna has been traditionally used for reduction in perspiration of hands and feet. The antifungal, antibacterial and staining properties of henna are ascribed to the lawson present in it. Also, the tannin in henna extract is astringent and decreases perspiration. Henna thickens the hair and strengthens it. Also, henna extract alleviates itching of skin and in cases of burn, decreases burning sensation and pain.
Hyperhidrosis might be local (limited to one or few spots) or general. True general hyperhidrosis is rare; even profuse perspiration due to systemic diseases is usually more evident in certain spots. In fact, many cases of increase in perspiration observed by skin specialists are local hyperhidrosis of palmoplanar or axillary types.
Treatment of hyperhidrosis requires treatment of the underlying disease. The proposed treatments for cases of local hyperhidrosis include: local use of aluminum chloride or aluminum chlorhydroxide, iontophoresis, botulinum injection, oral anticholinergic drugs (like probantine), diltiazem, clonidine and surgery.
In a controlled, double-blind clinical trial, 66 patients with palmoplanar hyperhidrosis were randomly asked to apply either henna extract or aluminum chloride 20% every night for one week. Response to treatment in the henna extract group was reported as 63.6% and in aluminum chloride 60.6%, which was not a significant difference (p=0.7). The most prevalent adverse reaction in the aluminum chloride group was dryness of hand palms (36.7%) along with other symptoms such as burning, itching and dermatitis. The most prevalent adverse reaction in the henna extract was temporary colorization of the skin (66.7%). Response to treatment was the same in both genders and all ages. The researchers came to the conclusion that in cases of palmoplanar hyperhidrosis, henna extract is a desirable alternative for aluminum chloride solution.