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.

General considerations

·  Immediate hypersensitivity disease: serum IgE elevated in 80% of patients; all patients have positive skin, RAST, and other allergy tests; positive family history in two-thirds of eczema patients; many develop allergic rhinitis and/or asthma; most improve with elimination diet.

· Physiological and anatomical abnormalities of skin: type of abnormality determines manner in which atopic dermatitis (AD) is manifested in each patient – lowered threshold to itch stimuli (substance P excess ?); hypersensitivity to alpha-adrenergic agonists and cholinergic agents via partial beta-adrenergic blockade (receptor site insensitivity); dry, hyperkeratotic skin with decreased water-holding capacity (dry-zinc or thyroid deficiency); hyperkeratotic – vitamin A deficiency ?); tendency to lichenify in response to rubbing and scratching (membrane fragility ?); skin heavily colonized by bacteria (coagulase-positive Staphylococcus aureus) (immune dysfunction).

· Dennie’s sign (accentuated double pleat below margin of lower eyelid) and tendency towards vasoconstriction provoked by physical pressure (‘white dermatographism’).

· Immunological abnormalities: leukocytes have decreased cAMP due to increased cyclic AMP-phosphodiesterase activity and decreased prostaglandin precursors; decreased intracellular cAMP increases histamine release and decreases bactericidal activity.

·  Defect in serum bactericidal activity: (alternative complement pathway, ACP): inulin-containing herbs (burdock root [Arctium lappa] and dandelion root [Taraxacum officinale]) may restore bactericidal activity and increase cAMP – inulin activates ACP.

· Predominance of pathogenic Staphylococcus aureus in skin flora in 90% of patients – increased susceptibility to Staphylococcus infections.

· Cell-mediated immunity defects: increased susceptibility to cutaneous herpes simplex, vaccinia, molluscum contagiosum, and verucca vulgaris infections; reduced delayed-type hypersensitivity, cutaneous anergy, and decreased in vitro lymphocyte reactivity to mitogens and antigens; cell-mediated defects normalise during remission and abnormalise again during recurrences.

·  ICIM often begin with the ‘ICIM Blood Analysis’ which analyses a drop of blood under a high resolution microscope. This is very helpful when trying to determine immunological, gut permeability, signs of fungal forms, maldigestion and toxicity related factors.  For further information see ICIM Blood Analysis.

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 and DHA
-          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.

For further information on Eczema and ICIM Blood Analysis contact the Irish Centre of Integrated Medicine on 045 844 819 or e-mail info@icim.ie

Tags: Skin Conditions