Posts Tagged ‘bacterial endotoxin’

Hygiene Hypothesis revisited

Sunday, January 22nd, 2012

The recent epidemic of allergic disease seen in developed countries has been difficult to explain. We have seen four-fold increases in allergic diseases such as asthma, rhinitis, eczema and food allergies. Changes in lifestyle and eating habits seem to be implicated and clean, sterile and infection-free “westernised” homes seem to be the probable trigger. One’s first year of life plays a pivotal role in allergic sensitisation and if an infant’s immature immune system is not correctly stimulated, it can transform into allergy-prone mode, particularly in children with a genetic predisposition to develop allergies (this is called atopy).

 Factors that seem to reduce the likelihood of developing allergies include:

  • A home with 2 or more older siblings living in close proximity.
  • Pet ownership (especially dogs & early exposure to animal farms)
  • Exposure to parasite or hookworm infections (IgE was designed to combat worms).
  • Exclusive breastfeeding for 4 months (confers immune protection).
  • Early introduction of probiotic bacteria (acidophilus GG promotes gut immunity)
  • Micro-bacteria in spoilt food and drinking water
  • Dietary anti-oxidants, folate, fish oils and vitamins (such as Beta carotene)

 Factors that seem to promote allergic sensitisation include:

  • Lack of older siblings (who carry germs that switch off allergies)
  • Advancing parental age (aging genes predispose to allergy)
  • Birth by Caesarian section (lacks exposure to protective vagina bacteria).
  • Sterile Westernised homes (no germs to stimulate the immune system)
  • Predominantly sterile indoor environment (no exposure to dirt )
  • No household pets (faecal endotoxins & germs)
  • Early use of paracetamol and antibiotics (alter immune responses)
  • Lack sun exposure (lack of Vitamin D effects genes)
  • Obesity and sedentary lifestyle (smaller lungs cause asthma).
  • Parental indoor smoking (maternal during pregnancy and infancy).
  • Withholding of potentially allergenic foods such as peanut and egg exposure in early infancy (4 months is better than 12 months).
  • Diesel exhaust particles (make aero-allergens more potent)

 Reference:  Tan T, Ellis JA, Saffery R, Allen KJ. The role of genetics and environment in the rise of childhood food allergy. Clinical and Experimental Allergy 2012 (42) 20-29

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Skin germ makes eczema worse

Wednesday, April 7th, 2010

The Staphylococcus Aureus (Staph) skin germ plays a pivotal role in aggravating moderate to severe atopic eczema especially in children.  Eczema first occurs in infancy but may persist through childhood into adulthood. Many factors are implicated and certain and promote eczema such as our gene makeup (atopy), skin allergy (to dust mites, pet dander and food allergens). The common skin Staph bacterium carried by us on the skin seems to play an important role in triggering eczema exacerbations.  While 10 and 40% of the general population carry the germ Staph on their skin, a whopping 90% of eczema sufferers have this germ on their skin. Studies reveal that 30% of moderate eczema sufferers are allergic to a bacterial endotoxin produced by the Staph, while in severe and difficult to control eczema, up to 68% of children will have an allergy to this germ. The Staph also seems to make established eczema more difficult to treat by increasing skin resistance to therapeutic steroid creams – they just don’t seem to work as well if there is a Staph infection present.

Studies show that systematically eradicating the Staph from the skin will make the eczema easier to control and  ultimately clear. In an established infection, the eczema will spread rapidly appearing bright red, crusty, weepy and blistered. The Staph can also persist by being harboured in the nasal passages, under dirty finger nails and in moist skin creases. Fortunately most Staph will respond to antibiotic skin creams such as Mupirocin (Naseptin), Fusidic acid (Fucidin) as well as to antiseptic skin disinfectants such as povidine iodine (Betadine), hydrogen peroxide, potassium permanganate and chlorhexidine (Hibitane). The beneficial effect of using sodium hypochlorite (found in bleech) and silver impregnated garments has not been proven.  In established Staph infections presenting with Impetigo (skin honey crusts), Folliculitis (pimples and pustules) and Cellulitis (widespread skin surface infection), oral antibiotics such as Flucloxacillin, Erythromycin and Co-amoxyclav will effectively treat the skin infection (unless the superbug MRSA (Methicillin Resistant Staphylococcus Aureus) is present). Read more about managing eczema

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