Psoriasis, eczema, what’s the difference?

If you’re suffering from red, itchy patches that literally have you ‘crawling out of your skin’, then perhaps the difference doesn’t mean much to you.  As it happens, though the two share similar symptoms, their causes are distinct.  Knowing which you suffer from is key in developing an effective strategy to select particular herbs for eczema or psoriasis.

psoriasis - Robbins Basic PathologyPsoriasis

Let’s start with psoriasis, which is a chronic, inflammatory dermatitis that most frequently appears on the elbows, knees, scalp, lower back, and even between the buttocks (the ‘intergluteal cleft’).  It is thought to be an auto-immune disorder, where the body’s immune cells attack healthy cells.  In the case of psoriasis, T-cells present in skin are stimulated by any number of offending antigens and begin to accumulate in the epidermis (the outer layer of the skin).  These cells begin to secrete inflammatory cytokines which produce symptoms of an ‘allergic response’ – swelling, redness – and growth factors that stimulate the skin’s keratinocytes. In normal skin, keratinocytes complete a growth cycle in approximately 28 days.  With psoriasis, this cycle goes into hyperdrive, with mature cells in 3-4 days.  This rapid proliferation produces the characteristic raised, red with white coat, scaly lesions.

Now that we understand the basics of psoriasis, we can select appropriate herbs.  Topical administration of herbs that are soothing, anti-inflammatory, and healing are important for local relief.  Look for natural, organic products containing: calendula (Calendula officinalis), St. John’s wort (Hypericum perforatum), plantain (Plantago major), licorice (Glycyrrhiza glabra), oats (Avena sativa).

Plantain
Plantain (Green Haven Estate)

For systemic healing, taking herbs internally is critical to get to the root of the issue.  For psoriasis, a few classes of herbs are appropriate here:

Immunomodulating:

Because psoriasis has an auto-immune component to it, herbs that normalize and tone the immune system are indicated:  astragalus root (Astragalus membranaceous) and reishi mushroom (Ganoderma lucidum) are good choices here.

burdock
Burdock (Green Haven Estate)

Liver/digestive support:

Some of the aforementioned antigens (=antibody generators) that trigger or exacerbate psoriasis may be circulating due to inadequate digestion and detoxification.  Therefore, liver and digestive herbs can be useful to help clear unwanted toxins: burdock root (Arctium lappa), yellow dock (Rumex crispus), Oregon grape root (Mahonia aquifolium).

Alterative:

Sometimes known as ‘blood cleansers’, these are a special class of herbs that help to clear toxins in an admittedly not-well-understood way.  All three herbs listed under liver/digestion are also alteratives, and to this list I would also add sarsaparilla (Smilax spp.) as an excellent choice.

Anti-inflammatory/healing:

Some of the herbs listed for topical use may also provide some benefit internally as well.  To these I would add: turmeric (Curcuma longa) and gotu kola (Centella asiatica).

gotu kola
Gotu kola (Green Haven Estate)

eczema - Robbins Basic PathologyEczema

Now, how about eczema?  In contrast to the auto-immune-mediated psoriasis, eczema is considered to be more of an allergic reaction, either to an ingested food/drug, or to a direct-contact substance (hence the alternate name ‘contact dermatitis’).  In contrast to psoriasis’s dry, scaly skin, eczema produces a red, edematous (fluid-filled) rash, sometimes with oozing plaque in advanced cases.  It is often itchy, hot to the touch, and uncomfortable.

Topically, herbs to soothe eczema will be similar to those mentioned for psoriasis.  Internally, however, there are some key differences in appropriate herbs.  Alteratives and anti-inflammatory herbs remain relevant, and to these I would add anti-histamines to alleviate some of the physical discomfort.  (think stinging nettle (Urtica dioica) and Baical skullcap (Scutellaria baicalensis).  Lymphatics are also important here because they move the metabolic ‘garbage’ left over from detoxification processes out of the body to clear the offending substance and reduce the allergic response.

Stinging nettles
Stinging nettles (Green Haven Estate)

Anti-histamines:

Overproduction of histamines causes the typical ‘allergic reaction’ symptoms such as swelling, rash, irritation.  Stinging nettle leaf (Urtica dioica) and Baical skullcap root (Scutellaria baicalensis) are two herbs with known anti-histamine activity.

Lymphatics:

Lymphatics are substances that promote movement of lymph throughout the body.  Lymph is fluid that transports immune cells and cellular waste products.  Herbs such as poke root (Phytolacca americana)*, calendula (Calendula officinalis), red root (Ceanothus americana) assist in ridding the body of irritants, toxins, and other waste products that may contribute to eczema outbreaks.

*poke root is a ‘low dose’, potentially toxic herb.  Use sparingly, preferably under the care of a trained professional.

For more detail on the genesis of eczema and additional herbal strategies, visit my latest Ask The Herbalist’s blog post.

I hope you’ve learned a little about differentiating specific herbs for eczema and psoriasis.  Any questions?  Scratch that itch and contact me!

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