Alternative names: birch tar oil, birch wood oil, black birch, chery birch, sweet birch oil, white birch.

taxonomic class

betulaceae

Common trade names

None known.

common forms

Available as dried bark, essential oil (bark, wood), and tea. Source

The active birch compounds are derived from the dried bark and twigs of the birch species Betula alba (Betula pendula), Betula verrucosa, Betula pubescens, and Betula tarda. Several species of birch trees are native to eastern North America, Europe, and parts of Russia.

Chemical components

Distillation of the bark of B. alba produces betulin, birch tar oil, creosol, cresol, guaiacol, isomeric hydrocarbons, phenol, pyrocatechol, turpentine oil, and xylenol. Avicularin, flavonoids, galactosyl-3 myricetol, glucuronil-3 quercetol, hyperoside and quercetin are found in the dried leaves. Sweet birch oil is produced by steam distillation of the water-softened bark of B. tarda. Methyl salicylate is released in the process. Sweet birch oil is composed almost entirely of methyl salicylate.

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Methyl salicylate has analgesic, anti-inflammatory and antipyretic properties. Hemostatic function in animals is affected by thromboplastic agents presumably found in B. pendula. The mechanism of action resembles that of human tissue thromboplastin. In other animal studies, birch has been shown to exert diuretic properties.

reported uses

Birch claims include the relief of headaches and other analgesic effects, as well as the treatment of various acute and chronic skin disorders, gastrointestinal disorders, and kidney stones. Essential oils are said to act against bladder infections, gout, neuralgia, rheumatism, and tuberculous cervical lymphadenitis. In veterinary medicine, birchwood essential oil has been used to treat various skin conditions.

Dose

Extracts or teas can be made by steeping 2 to 3 g of the bark in boiling water for 10 to 15 minutes; the infusion can be ingested several times a day.

Adverse reactions

Skin: acute contact dermatitis.

Event: allergic rhinitis.

Others: Cross-sensitization with other plant allergens, such as celery and mugwort pollen.

interactions

None reported.

Contraindications and precautions

Birch is contraindicated in pregnant or lactating patients. Use with caution in patients with seasonal allergic rhinitis or hypersensitivity to plant allergens.

Special Considerations

Monitor for signs and symptoms of an allergic reaction, particularly in patients with allergies to celery, mugwort, or other plants.

Alert Advise the patient to keep birch preparations out of the reach of children. Sweet birch oil is 98% methyl salicylate, which can be fatal to children when applied topically to the skin. Poisonings have been reported with as little as 4.7 g of topically applied methyl salicylate.

Advise the patient that topical preparations may irritate the skin and mucous membranes. Encourage him to report new or unusual dermatological manifestations.

Advise women to avoid the use of birch products during pregnancy or lactation.

Points of interest

Betulin is being evaluated for its antitumor properties.

In Germany, the leaves of B. pendula are used as a diuretic during irrigation therapy for urinary tract infections.

Commentary

Birch’s chemical compositions possess some interesting properties. However, until more clinical research is available, these agents have no role in modern medicine. The risk of hypersensitivity reactions makes OTC use of concern.