Allergies May Prevent Heart Attacks???

Research has been published suggesting an inverse relationship between serum IgE and heart attacks in the US population independent of coronary risk factors.

No kidding...

This conclusion was reached based analyzing 4002 participants between 2005-2006. They also detected that of the 7 "data-driven, prespecified allergen clusters," house dust mite was the only allergen cluster for which serum IgE is associated with reduced risk for heart attack.

For those wondering, serum IgE is a rough measure of how allergic a patient is generally speaking without any specification of what the patient may be allergic to. It is obtained by bloodwork (RAST or immunoCAP).

The higher the IgE levels, the more allergic a patient is generally speaking. However, one must keep in mind that it may still be possible to be allergic even if IgE is low or vice versa.

Also, although there appears to be a relationship between IgE and heart attacks, it is doubtful it reaches clinical significance for any given patient. Rather, such conclusions may apply to a general population. This study was also retrospective and as such, it would be nice if a new study now looked at a group of allergic patients and see how many suffer heart attacks in the future.

Such un-intuitive relationships just goes to show how complex the human body is where one thing doesn't cause one problem, but rather one thing may affect multiple different aspects of human health.

Now why would IgE and/or allergies in general influence heart attack risk?

Well heart attacks are due to vascular disease (blockage of the coronary artery). Vascular disease is thought to be influenced by how much inflammation is present in the body. The more inflammation present, the higher the risk of vascular disease which in turn increases heart attack rates.

One factor thought to influence the degree of inflammation present in the body is the immune system, and allergies is one part of the immune system.

As such, allergies could be a reflection of what the immune system is doing which in turn influences the degree of inflammation present in the body which in turn affects vascular disease which plays a role in heart attacks.

Reference:
Relation between objective measures of atopy and myocardial infarction in the United States. Journal of Allergy and Clinical Immunology. In Press Aug 27, 2012.

Child's Allergy Risk Higher If Same Sex Parent Has It

British researchers reported this month their findings that a child is at higher risk of allergies if the same sex parent has allergies. In other words, if a father has bad allergies, his sons are at higher risk for them and if a mother has bad allergies, than her daughters are at higher risk for allergy problems.

They based their findings following 1456 children examined at 1, 2, 4, 10, and 18 years of age. History of asthma, eczema, rhinitis, and environmental factors was obtained and skin prick tests were carried out at ages 4, 10, and 18 years, and total IgE measurement was carried out at 10 and 18 years. Parental history of allergic disease was assessed soon after the birth of the child, when maternal IgE levels were also measured.

Keep in mind that the appearance of allergy in a child is not wholly based on genetics but does have some environmental basis as well.

However, the association of gender is a new twist on whether a child will develop allergies or not.

Reference:
The effect of parental allergy on childhood allergic diseases depends on the sex of the child. The Journal of Allergy and Clinical Immunology Volume 130, Issue 2 , Pages 427-434.e6, August 2012

Head CT Scans Increase Risk of Cancer in Kids

By how much?

Brain tumor/cancer risk was 3X greater than the general population in children who received two to three CT scans of the head.

And the chance of developing leukemia was three times as great for children who received five to 10 CT scans of the head.

In the study published in Lancet, the researchers examined 176,587 children who had received a CT scan before age 22 and looked at their medical history for an average of 10 years afterward.

Though the risk sounds "high," the overall risk is still relatively small and CT scans should still be performed if medically warranted.

Phrased another way, the risk corresponds to one additional case of leukemia in the 10 years after the first scan for every 10,000 patients younger than 10 who were scanned or an extra case of brain cancer for every 30,000 children scanned.

Even so, the study does illustrate that CT scans should not be ordered unless there's a very good reason to do so, especially in children given they are more radiosensitive compared to adults.

In the ENT world, the most common reason to order a CT scan is to evaluate for sinusitis.

My own personal preference is to obtain one in children if and only if all other sinusitis interventions have already been performed.

Such "sinusitis" interventions include:

• Allergy intervention (steroid and/or anti-histamine nasal sprays)
• Failure to respond to antibiotics
• Adenoidectomy (if large adenoids present which can be determined on endoscopy)
• Turbinate Reduction (if turbinates are enlarged)
• Check for cystic fibrosis and primary ciliary dyskinesia

If above interventions have been performed, only than would I consider a CT scan of the sinuses.

Some (other ENTs) may argue that CT scan of the sinuses should be performed early as a more directed intervention can than be performed.

My argument against that is, EVEN if the CT sinus comes back abnormal, I STILL would perform the above interventions first because often the above interventions will clear up and sinus abnormality seen on a CT scan.

Only when everything else has been tried would I consider sinus surgery in a child and only than would a CT sinus be justified in my mind.

However, there are certain other situations I may consider getting a CT scan relatively quickly...

• If I find a sino-nasal mass on exam concerning for tumor or nasal polyps
• Congenital hearing loss
• Cholesteatoma (tumor of the ear)
• "Significant" Facial Trauma (ie, not just for a simple broken nose)


Reference:
Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: a retrospective cohort study. The Lancet. 7 June 2012. doi:10.1016/S0140-6736(12)60815-0

Source:
Children's CT Scans Pose Cancer Risk. Wall Street Journal 6/6/12