• Toys that bear the asthma- and allergy-friendly certification have actually undergone scientific tests to demonstrate their safety for children with asthma and allergic rhinitis. Most of these toys are either washable (to remove offending allergens) or constructed of allergy-free materials.
• Apparently it “pays” to breastfeed your infant. A recent analysis by the Environmental Protection Agency found that breastfeeding leads to an increase in IQ by six points. They then correlated this with a known ratio between lifetime earnings and IQ and determined that a breastfed child should earn $65,000 more than a bottle-fed companion.
• Mistletoe has potential to cause contact dermatitis akin to poison ivy. It generally requires repeated skin contact to elicit this response. Note: Kissing underneath it is still medically safe.
Dear Dr. K: My cousin who lives in New Hampshire has developed an allergy to water. For the past two years she gets extremely itchy every time she showers, or whenever water touches her skin – but there is no rash. She has seen an allergist, but the various prescribed antihistamines haven’t helped. Do you have any suggestions?
Yes, I do. First of all it sounds as if your cousin has idiopathic aquagenic pruritis. Usually, this condition just develops out of the blue, but it can be caused by some serious conditions such as Hodgkin’s disease, polycythemia vera, other blood disorders, and by some drugs. She needs to have her primary doctor exclude these possibilities.
If the water pruritis isn’t secondary to some other disease, then it is felt to be caused by inappropriate activation of the autonomic (automatic) nervous system. These nerves release neurotransmitters that seem to be the source of the itch. Since histamine is not generally released by these nerves, the use of antihistamines doesn’t usually stop the pruritis.
Some patients benefit by alkalinization of the tap water in their home. This possible benefit can be tested by taking a bath in water containing several boxes of baking soda.
Other patients benefit from the use of narrow-band UVB light phototherapy.
The treatment that has had the best success is the use of the beta-blocker drug propranolol. The beta system is a major component of the autonomic nervous system.
Finally, some people are helped by the alpha agonist (stimulator) clonidine. The alpha system is also part of the autonomic nervous system.
A recent breakthrough in understanding people with chronic rhino-sinusitis was made at the University of Zurich.
Scientists there found that patients with severe nasal allergy, especially those with nasal polyps, have a defective epithelial cell barrier lining their nose.
The normal epithelium of the nose has tight junctions between the individual cells consisting of trans-membrane scaffolding cells. This can best be visualized as being like the grout between individual floor tiles in your home.
The Zurich researchers found a direct correlation between the severity of the rhinitis and/or polyps and the scarcity of the tight junction proteins. The reduction of these grout proteins allows two bad things to happen: First it allows easy access of allergens into the depth of the nasal tissue and, second, it allows wider dispersal of inflammatory molecules which worsen symptoms.
This discovery is probably not too surprising based on a similar situation in the skin of people with eczema and their lack of the intra-cellular grout called filagrin, which was previously discussed in this newsletter.
The scientists in Zurich are hopeful that this discovery will lead to new therapies that will restore the barrier function of the epithelium.
The Mayo Clinic Proceedings recently had a review of adverse reactions to the various types and routes of injection of the most common iodinated contrast agents used in obtaining X-rays. Contrast media are usually safe, but severe reactions can occur.
The injection sites – in order of increasing risk for reaction – include into tissue spaces or cavities, into an artery and into a vein.
The two main causes for acute reactions are allergic and anaphylactoid, with the latter accounting for the vast majority of events.
The allergic mechanism involves the allergic antibody IgE, and requires that a person have some previous exposure to contrast media that can lead to the development of the allergy. The anaphylactoid mechanism involves activation of defensive complement proteins by the immune system, and requires no previous exposure to cause an adverse event.
Regardless of the mechanism, the symptoms are the same: rash, hives, angioedema, wheezing and possible shock.
Risk factors identify people with the greatest risk of adverse reactions: a history of asthma, a history of a prior reaction to contrast media and a history of being an allergic individual. Persons who are at higher risk should be pre-medicated. A pre-treatment regimen of medications that has had the best success in preventing reactions includes giving corticosteroids in several doses, starting the day before the X-ray test. Next, two types of antihistamines are given shortly before the test – an H-1 blocker such as Benadryl and an H-2 blocker such as Zantac.
Use of this three-pronged prevention eliminates most reactions or lessens their severity.
Acknowledged in the classic poem by Robert Burns, “Ode to a Louse,” lice are definitely an unfortunate part of communal life, especially involving school attendance. But take hope. There is a new treatment available that has been a health boon for several reasons.
With existing medicines for treating lice there are two major problems: resistance and allergy. Unfortunately, many species of head lice have developed resistance to the standard therapies; that is, they aren’t killed by the once-effective therapies such as permethrin and pyrethrin. Second-line drugs such as lindane and malathion don’t incur resistance, but their use is restricted due to safety concerns.
The traditional therapies permethrin and pyrethrin are found in a variety of products, both over the counter and by prescription, (such as Nix). Their use, however, has always been difficult in allergic individuals because they cross-react with ragweed and can lead to skin rashes, hives and even asthma.
The new therapy utilizes the drug Ivermectin in a topical hair lotion. Ivermectin has been used for many years in an oral form to treat a wide variety of intestinal worm infestations. Only recently did scientists think to try it in a topical form to treat lice. In a research study published in the New England Journal of Medicine it was shown that a single 10-minute application was almost uniformly effective in eliminating the lice. Additionally, it was safe in individuals with allergies.