ECZEMA (ATOPIC DERMATITIS)

Eczema is a common condition which affects 2.4 – 7 % of the population. It is described as a chronic, pruritic, inflammatory skin condition. The skin is dry and hyperkeratotic; lesions include excoriations, papules, eczema (patches of erythema, exudation, and scaling with small vesicles formed within the epidermis), and lichenification (hyperpigmented plaques of thickened skin with accentuated furrows); scratching and rubbing lead to lichenification, most commonly in antecubital and popliteal flexures; personal or family history of atopy.

Therapeutic considerations

·         Food allergy: major role in atopic dermatitis; breast-feeding acts as prophylaxis against atopic dermatitis (and allergies in general); breast-fed infants develop atopic dermatitis due to transfer of antigens in breast milk – mother should avoid common food allergens (milk, eggs, peanuts, fish, soy, wheat, citrus, and chocolate); in older or formula-fed infants, milk eggs, and peanuts are the most common foods inducing atopic dermatitis; virtually any food can be offending agent; diagnosis of food allergy – best via elimination diet and challenge; lab methods to identify food allergens in eczema; ELISA IgE and IgG4. Food allergies linked to ‘leaky gut’, i.e. increased gut permeability with increased antigen load on immune system and developing additional allergies; eliminating allergenic foods can stop development of new allergies; avoiding offending foods for 1 year may eradicate allergy – loss rate after 1 year is 26% for five major allergens (egg, milk, wheat, soy, peanut) and 66% for other foods.

·         Candida albicans: gastrointestinal (GI) overgrowth is the causative factor in allergies atopic dermatitis; elevated anti-Candida antibodies are common in atopy; severity of lesions correlates with level of IgE antibodies to Candida; anti-Candida therapy may significantly improve atopic dermatitis.

·          Essential fatty acids (EFA) and prostaglandin metabolism: AD patients have altered EFA and prostaglandin metabolism – increased linoleic acid levels to be increased with decreased longer-chain PUFAs (gamma-linolenic acid and arachidonic acid) and omega-3 oils (eicosapentaenoic acid [EPA] and docosahexanoic acid [DHA]); proportions of linoleic acid in total plasma lipids and phospholipids are greater, and those of oleic acid lower, than normal in AD patients; ratio of omega-3 to omega 6 fatty acids is lower in AD patients; no significant decreases in proportions of dihomogamma-linolenic acid and arachidonic acid observed in plasma lipids of atopic patients, suggesting delta-6-desaturase is not impaired; ‘fish oil’, providing EPA and DHA or simply eating more fatty fish (mackerel, herring, salmon), increases omega-3 fatty acids in membrane phospholipids; degree of clinical improvement correlates with increased DHA in serum phospholipids; fish oils are more effective in raising DHA than flaxseed oil – EPA/DHA supplements or increasing consumption of cold-water fish may produce better results than flaxseed oil.

·         Inhibiting excess histamine release: agents which stimulate cAMP production and/or inhibit cAMP phosphodiesterase reduce inflammatory process in AD by reducing shunting to histamine; Coleus forskohlii strongly enhances cAMP; many botanicals inhibit diesterase – licorice (Glycyrrhiza glabra) shows marked activity; flavonoids also inhibit cAMP phosphodiesterase – quercetin and hyperoside, the flavanes orientin and vitexin, and the flavanone naringen; the common flavanol, rutin, has < 1/10 activity of quercetin; flavonoid extracts from Vaccinium myrtillus, Rosa damascene, Ruta graveolans, Prunus spinosa and Crataegus pentagyna are the most potent inhibitors of cAMP phosphodiesterase and also inhibit mast cell degranulation; flavonoid-rich extracts (grape seed, pine bark, green tea, Ginkgo biloba) may prove helpful; Ginkgo terpenes (ginkgolides) antagonize platelet-activating factor (PAF), the key mediator in AD; PAF plays central role in neutrophil activation, increasing vascular permeability, smooth muscle contraction (bronchoconstriction) and reduced coronary blood flow; ginkgolides compete with PAF for binding sites; mixtures of ginkgolides and Ginkgo biloba extract (standardised to 24% flavonglycosides and 6% terpenoids) demonstrate significant anti-allergy effects.

·         Zinc: low zinc is common in AD; EFA metabolism is essential in AD (Zn required for delta-6-desaturase).

Botanical medicines

Two categories below – internal and external.

·          Licorice (Glycyrrhiza glabra): useful in either application; internally, licorice has anti-inflammatory and anti-allergic effects.

·         Chinese herbal formula: used in double-blind crossover trials; contains licorice, plus Ledebouriealla seseloides, Potentilla chinensis, Clematis chenisis, Clematis armandi, Rehmania glutinosa, Paeonia lactiflora, Lophatherum gracile, Dictamnus dasycarpus, Tribulus terrestris, Schizonepeta tenuiflora – significant objective and subjective improvement in adults and children but many patients complained about unpalatability of decoction; effect similar to topical hydrocortisone for eczema, contact and allergic dermatitis, and psoriasis.

Miscellaneous factors

·          Hypothyroid patients with eczema respond well to thyroid.

·         Scratching: extremely detrimental to AD – breaks skin, aiding bacterial ingress, and promotes lichenification; factors which limit itching promote healing and prevent recurrence.

·          Emotional tension: aggravates itching in AD; AD patients show higher anxiety, hostility, and neurosis than matched controls.

Therapeutic approach

Relieve and prevent itching while treating underlying metabolic abnormalities; detect and control food and environmental allergies; normalise prostaglandin metabolism; balance immune system.

·          Conduct the ICIM Blood Analysis followed by Naturopathic Consultation to help undercover underlying factors.

·         Diet: 4-day rotation diet, eliminating all major allergens (milk, eggs, peanuts in 81% of cases); as patient improves, slowly reintroduce allergens and reduce stringency of rotation diet; limit animal products; add fatty fish (salmon, mackerel, herring, halibut – so long as patient has no known allergies to fish).

·          Supplements:

-         Vitamin A

-          Vitamin E

-         Zinc

-          Quercetin

-          EPA andDHA

-          Evening primrose oil

·         Botanicals

-          Arctium lappa or Taraxacum officinale

-         Coleus forskohlii

-          Glycyrrhiza glabra

·         Topical treatment: glycyrrhetinic acid-containing commercial preparations; chamomile preparations; witch hazel preparations.

·         Helpful tips: avoid sweating and rough-textured clothing; wash clothing with mild soaps only and rinse thoroughly; avoid exposure to chemical irritants; local application of soothing lotions ameliorates itching (zinc oxide); but minimise greasy preparations that block the sweat ducts.

·          Psychological: determine if patient has significant anxiety, hostility, or neurosis, refer to counsellor for therapy as needed.