kava and Exanthema

Aqueous kava root preparations have been consumed in the South Pacific as an apparently safe ceremonial and cultural drink for centuries. However, several reports of hepatotoxicity have been linked to the consumption of kava extracts in Western countries, where mainly ethanolic or acetonic extracts are used. The mechanism of toxicity has not been established, although several theories have been put forward. The composition of the major constituents, the kava lactones, varies according to preparation method and species of kava plant, and thus, the toxicity of the individual lactones has been tested in order to establish whether a single lactone or a certain composition of lactones may be responsible for the increased prevalence of kava-induced hepatotoxicity in Western countries. However, no such conclusion has been made on the basis of current data. Inhibition or induction of the major metabolizing enzymes, which might result in drug interactions, has also gained attention, but ambiguous results have been reported. On the basis of the chemical structures of kava constituents, the formation of reactive metabolites has also been suggested as an explanation of toxicity. Furthermore, skin rash is a side effect in kava consumers, which may be indicative of the formation of reactive metabolites and covalent binding to skin proteins leading to immune-mediated responses. Reactive metabolites of kava lactones have been identified in vitro as glutathione (GSH) conjugates and in vivo as mercapturates excreted in urine. Addition of GSH to kava extracts has been shown to reduce cytotoxicity in vitro, which suggests the presence of inherently reactive constituents. Only a few studies have investigated the toxicity of the minor constituents present in kava extract, such as pipermethystine and the flavokavains, where some have been shown to display higher in vitro cytotoxicity than the lactones. To date, there remains no indisputable reason for the increased prevalence of kava-induced hepatotoxicity in Western countries.

Topics: Animals; Chemical and Drug Induced Liver Injury; Cytochrome P-450 Enzyme System; Exanthema; Glutathione; Humans; Kava; Lactones; Plant Roots

Topics: Acute Disease; Aftercare; Anti-Inflammatory Agents; Biopsy; Diagnosis, Differential; Erythema; Exanthema; Female; Humans; Kava; Plants, Medicinal; Prednisolone; Pruritus; Skin Diseases; Systemic Inflammatory Response Syndrome; Treatment Outcome; Urticaria; Young Adult

Supplement use is prevalent, and its use is increasing among older adults. Dermatologists need to be aware of the adverse cutaneous effects that can result from herbal supplement use. A 55-year-old man presented with an eruption in a sebotropic distribution after consuming kava kava for 3 weeks, which resolved after discontinuation of the supplement. This case highlights the need for clinicians to consider kava kava in the differential of sebotropic eruptions. The biology, mechanism of action, and potential systemic and cutaneous effects of kava kava are reviewed.

Topics: Dietary Supplements; Drug Eruptions; Erythema; Exanthema; Humans; Kava; Male; Middle Aged; Phytotherapy; Plant Preparations; Sebaceous Glands