Herbal Therapy For Skin Diseases Part-II
Arnica - an anti-inflammatory herb
Steroid sparing effect of herbs
Herbal therapy is defined as the use of plants or plant extracts for medicinal purposes (especially plants that are not part of the normal diet).
In my previous hub, I had described the medicinal benefits of herbs in various common skin problems.
Steroids are the mainstay of treatment in most skin eczemas and allergies. Skin conditions take long to improve. But long-term use of topical corticosteroids can lead to thinning of skin, appearance of wrinkles, excessive hair growth on the skin (hirsutism) and appearance of fine red veins, the telangiectasias.
There is much attention to the use of topical herbal preparations as the corticosteroid sparing agents for the treatment of skin inflammation. Herbs like arnica, chamomile, colloidal oatmeal and pansy flower infusions reduce the dosage of steroids and duration of therapy in various skin allergies.
Arnica - the anti inflammatory agent
Arnica comes from the dried flowers of Arnica montana or other arnica species. Although oral intake, even in small amounts, can cause severe health hazards, external application of arnica is safe and effective.
Being an anti-inflammatory agent, arnica is used to rub into sore muscles and joints, bruises, insect bites, boils, infected gums, acne eruptions and haemorrhoids, seborrheic dermatitis and psoriasis.
When used as a compress, 1 tbsp (15ml) of tincture is mixed in 500ml of water; if used as an infusion, 2 gms of dried arnica is mixed in 100 ml of water. The cream or ointment preparation should contain a maximum of 15% arnica oil or 20-25% tincture.
Its active ingredients are the sesquiterpene lactones.
Arnica should not be used on open wounds or broken skin. Its application can lead to contact sensitivity in those allergic to it or if used in stronger concentrations or for longer periods than recommended.
German chamomile - the all purpose herb
German chamomile - the all purpose herb
German chamomile (M.recutita) a member of the daisy family, has been used for centuries, internally and externally for almost all ailments.
Topical chamomile is comparable to a mild steroid 0.025% hydrocortisone, and helps improve contact dermatitis, reduce surface area and healing time of wounds and has anti-microbial properties.
However, it can lead to a severe allergic reaction in individuals sensitive to its contents.
The anti-inflammatory, wound healing and antimicrobial effects of german chamomile are attributed to a blue essential oil that contains sesquiterpene alcohol, alpha bisabolol, chamazulene and flavonoids. These natural constituents inhibit the enzymes cyclo-oxygenase and lipoxygenase that lead to inflammation, swelling and redness. The flavonoids also inhibit release of histamine, the chief component in allergic reactions. Bisabolol promotes early recovery of wounds.
Mucilage containing herbs
Several herbs contain a substance called mucilage that helps to soothe the reddened and irritated skin and also to moisturize it.
Mucilage has hygroscopic properties and swells into a gooey mass when in contact with water, thus soothes dry or mildly inflamed skin. The layer of mucilage itself also dries up and can be used as herbal bandage for minor wounds.
Such mucilaginous herbs include marshmallow, flax, English plantain, fenugreek, heartsease, mullein and slippery elm.
Oatmeal baths are very popular for their soothing and itch relieving effects. Colloidal oatmeal (Avena sativa) has a hygroscopic effect and swells up into a gooey mass when mixed with liquid, forming a layer on the skin to seal its moisture content.
This soothing and moisturizing effect is attributed to the gluten content in the plant.
Oatmeal based body washes and creams are commonly indicated for atopic dermatitis and idiopathic itching (of unknown cause) in elderly.
Medicinal uses and adverse effects of common herbs
Tea tree oil
Acne, fungal infections
Avoid during pregnancy
Bruises, insect bites
Poisonous on oral intake
Herbs notable for their tannin content include witch hazel, Chinese rhubarb, oak bark, English walnut leaf, yellow dock, lavender, jambolana bark and St John's wort.
When applied to fresh oozing, weeping acute eczema, tannins coagulate the skin surface proteins which form a protective layer or scab or crust that reduces permeability to microbes and secretion of pus.
Amongst the tannin-rich herbs, witch hazel extract is most commonly used to reduce redness and itching in atopic dermatitis.
Pansy flower - a natural remedy
Pansy flower infusion has beneficial effects in seborrheic dermatitis, a common type of eczema, especially in infants.
The infusion is made by mixing 1 to 2 tsp of flowers per cup of water and is used as a wet dressing.
The major active constituent being salicylic acid in very low concentrations (around 0.3%). It also contains saponins and mucilage that soften the hard eczematous crusts and have a soothing effect.
Adverse effects of Herbal Therapy
It is a common myth that, because herbs are "natural", they are free of all side-effects.
Herbal therapies vary greatly in their therapeutic indices, but may cause serious adverse effects.
The most common adverse effect of herbal preparations is contact allergy. Severe itching, redness and even painful blisters can develop at the site where the herbal preparation has been applied.
To prevent this adverse reaction, if you wish to use any "natural", organic preparation with herbal extracts, first apply a small amount of it either on your back or behind your ear lobe as a small patch. If the area becomes itchy, develops redness or shows signs of eczema within 48 hours of application, then it means "the Patch test" is positive and that you are allergic to the particular natural extract, so should avoid using it.
Other skin reactions reported from the use of herbal products include generalized redness or erythroderma and Stevens-Johnson syndrome, a life threatening, blistering allergic reaction.
Chinese herbal medicines can lead to severe liver damage and acute liver failure on oral intake.
Reversible dilated cardiomyopathy has been documented in a patient after treatment of her atopic dermatitis with a herbal tea.
Many herbal preparations contain heavy metals such as lead, arsenic and mercury that can cause harm to our body.
Drug interactions with prescription medicines
The immunomodulating effects of echinacea, astragalus, licorice, alfalfa sprouts, vitamin-E and zinc may cause decrease in efficacy of steroids and immunosuppressant medications.
There are herbs like echinacea, chaparral, germander and life root that are hepatotoxic and should not be used with anti-metabolite methotrexate, a medicine commonly used to treat psoriasis.
Herbs containing gamma linolenic acid such as evening primerose oil used to treat dryness, psoriasis and eczema, lower seizure threshold and can precipitate epileptic fits. Therefore dosage of anti-convulsant medicines may need to be increased when both have to be used together.
Herbal medicine is indeed a gift to mankind from mother nature, but like every coin has two faces, herbs can also cause severe adverse effects. Proper and judicious use of this therapy can cure the most complicated and difficult to treat conditions.
Reference source :
"Herbal therapy in Dermatology" by Monica K. Bedi, MD; Philip D. Shenefelt, MD
as published in Archives of Dermatology/Vol138, FEB 2002.