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

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

Tick bites trigger anaphylaxis to red meat

Dr. Adrian Morris — Sat, 02 Jul 2011 17:36:29 +0000

Allergy to red mammalian meat is relatively common in Africa and so are tick bites. I was recently shown a study by Platts Mills et al from USA in 2011 in which they suggested there may be a link between tick bites by the Amblyomma species of North American tick and the development of IgE antibodies to a galactoside common to mammalian meat (beef, pork and lamb) and ticks. This IgE antibody then leads to anaphylactic sensitisation to mammalian red meat with angioedema and urticaria or hives. 80% of the people studied who had developed sensitisation and allergies to red meat reported previously being bitten by a tick. To confuse the issue, the allergic reactions are often delayed occuring 3 to 6 hours after eating red meat, Similar reactions have been reported following tick bites in Australia. This “alpha Gal” IgE antibody production is switched on by tick bites and could explain the relatively high incidence of red meat allergy seen in indiginous Africans as ticks and tick bites are very common in Subsaharan African.

Study by Platts Mills et al (2008)

Latest research on tick bites and meat allergy

Peanuts allergy cure is here!

Dr. Adrian Morris — Sat, 17 Oct 2009 07:04:07 +0000

In a recent peanut allergy study at Addenbrookes Hospital in Cambridge, traces of peanut flour were used to desensitise 18 highly peanut allergic children. At the end of the study conducted in a controlled hospital environment, they were able to consume 12 peanuts each without any allergic reaction. The study involved eating minute trace amounts of peanut flour mixed with food or drinks on a daily basis to slowly induce peanut tolerance. Then at regular 2 weekly intervals the peanut flour dose was doubled so that by the 10th hospital visit, they each ate 5-6 peanuts each without reacting on allergy testing. But to maintain thispeanut tolerance they will have to continue eating peanuts regularly on a daily basis, otherwise they may lose this tolerance and their peanut allergy recur.

WARNING: This was a highly controlled study in hospital and peanut allergic children should not be given peanut flour unsupervised!

http://news.bbc.co.uk/2/hi/health/7899383.stm