Dr. Adrian Morris of Surrey Allergy Clinic Tests and Treats allergies

Hygiene Hypothesis revisited

Dr. Adrian Morris — Sun, 22 Jan 2012 18:54:43 +0000

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

Christmas tree allergy, a cause for your sneeze.

Dr. Adrian Morris — Sun, 25 Dec 2011 20:30:28 +0000

For many years indoor Christmas trees have bee suspected to be a source of allergen induced asthma, rhinitis and respiratory problems during the period from mid December to early January. It was thought that coniferous tree pollen, incidental grass and weed pollens on the tree and oleoresins secreted by Fir trees were to blame. However a recent study in the US, has found that coniferous Christmas trees carry and sustain significant amounts of mould spores. Common allergenic moulds such as Cladosporium, Aspergillus, Alternaria and Penicillium are found in significant amounts on Christmas trees and raise indorr mould levels from 300 to 5000 spores per cubic metre of indoor air. Exposure to the spores trigger chronic respiratory conditions such as allergic asthma, rhino-sinusitis and chronic bronchitis (COPD). Spraying the tree with a mist containing household bleech such as Milton (sodium hypochlorite) kills off moulds and prevents their growth on the trees and subsequent indoor mould contamination.

Reference: Identification of mold on seasonal indoor Coniferous trees. Annals of Allergy, Asthma & Immunology 2011 106:6: 543-544

Allergy to clothing dye

Dr. Adrian Morris — Mon, 12 Dec 2011 06:25:55 +0000

Although often suspected by many clients as being the cause for localized body rashes, we hardly ever come across anyone with a confirmed allergy to commercial pigment dyes in clothing. One is more likely to develop contact dermatitis from dyes and rubber found in leather footwear, paraphenylene diamine (PPD) in hair dye and latex elastic in underwear. Detergent residues left in clothing can also irritate eczema-prone skin, causing it to flare up, and animal fibers such as wool, silk, mohair and fur in clothing can cause allergies. Cotton is the least allergenic clothing fiber. Most non toxic commercial clothing dyes are quite harmless, but occasionally reactions can be attributed to a particular type of dispersal dye (Disperse Blue 106 and 124) and formaldehyde residues found in new clothing, however these are usually removed after a few washes. Sweating and tight fitting clothing increases the likelihood of a reaction in dermatitis prone people.

Reference: Clothing Dye Allergy

Iodine in shellfish does not cause allergies.

Dr. Adrian Morris — Tue, 01 Nov 2011 14:34:16 +0000

There is a well established myth that fish and shellfish allergy is linked to the iodine content of fish and that iodine allergy and shellfish allergy are interrelated. This is untrue.

Shellfish such as shrimp, prawn, crab and lobster are crustaceans (crawl around) and have a protein in their flesh that can cause allergies, they contain too little iodine to cause any problems. Mussels, clams and squid are members of the mollusc (snail) family and a protein in their flesh can also cause food allergies, but they do not contain enough iodine to be a problem. Shellfish can ingest a nasty flagellate organism which causes food poison and a toxic reaction with vomiting, diarrhoea and flushing (this is not an allergy).

Iodine allergy is unrealated to shellfish but iodine can cause a local skin reaction when exposed (contact dermatitis) or a more severe anaphylactic reaction when radiocontrast dye is injected into a vein during invasive radiological examinations such as an isotope scan or angiogram used for investigation of kidney, heart, bone and brain conditions. Many doctors dont realise this seafood myth and will still ask if you are allergic to shellfish before giving radiocontrast.

The common joint supplement Glucosamine taken to help arthritis symptoms, although processed from shellfish extract (crab, shrimp and lobster shells), can safely be taken by people with shellfish allergies according to the Mayo Clinic in the USA.

Reference: http://www.mayoclinic.com/health/shellfish-allergy/DS00987/DSECTION=prevention

Insect sting allergies

Dr. Adrian Morris — Mon, 03 Oct 2011 14:39:19 +0000

A recent venom allergy guideline¹ published by the British Society for Allergy and Clinical Immunology (BSACI) this year, makes interesting reading. They report a lifetime-risk between 60 and 90% for the UK population of being stung by a wasp (Vespid) or bee (Apis). Of those stung, up to 26% will report large painful local reactions, but significant allergic reactions only occur in about 7% of those stung (bee-keepers being a very high-risk group with severe reactions reported in 30% of those stung). Although wasp venom allergy is more common in the UK, bee-stings carry a higher risk for anaphylaxis. Any patient with a severe reaction to an insect sting should be tested for both bee and wasp venoms sensitivity, as dual-positive IgE antibodies to both insects occurs in 30%, even though they may report being clinically sensitive to only one insect. Venom desensitisation immunotherapy (VIT) or “allergy shots” are highly effective in those severely sensitive to insect stings, resulting in a cure for 95% of wasp and 80% of bee venom allery sufferers treated over the 3 year programme. Older people are more likely to develop life-threatening anaphylaxis and fatal allergic reactions (at an average age of 50 years). Children are less prone to have life-threatening allergic reactions to insects, and 80% of children with a mild venom allergy with tolerate further stings and outgrow their allergy. Once sensitised, reactions are likely to be the same in 45% stings, milder in 43% and more severe in only 12%. Fatal reactions after insect stings are rare (47 deaths in UK over a 10 year period from 1992-2001)

¹Reference: Krishna MT, Ewan PW, Diwakar L, Durham S, Frew AJ, Leech SC and Nasser SM. Diagnosis and management of hymenoptera venom allergy: British Society for Allergy and Clinical Immunology (BSACI) guidelines. Clinical and Experimental Allergy 2011:41; 1201-1220