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‘Allergic’ to bath water? Time to rule out disease and test various solutions

‘Allergic’ to bath water? Time to rule out disease and test various solutions

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.

‘Grout’ proteins: more is better of these gatekeeper cells

‘Grout’ proteins: more is better of these gatekeeper cells

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.

Pre-medicating can head off injected contrast reaction

Pre-medicating can head off injected contrast reaction

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.

Cheers for the terminator – a better, safer, lice remover

Cheers for the terminator – a better, safer, lice remover

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.

Q-Tips: Steroids and height

Q-Tips: Steroids and height

The European Respiratory Society completed a long-term study on the effect of extended use of inhaled steroids on the ultimate height of asthmatic children. They found that in children with moderate asthma who required daily use of inhaled steroids over many years, their ultimate adult height was within one centimeter of that expected.

Q-Tips: RSV, asthma

Q-Tips: RSV, asthma

A high correlation exists between having RSV (respiratory syncytial virus) infection and developing childhood asthma. Research is being done to determine whether latent asthma predisposes to catching RSV, or whether RSV activates latent asthma.

Q-Tips: COPD

Q-Tips: COPD

The triotropium inhaler has been used for some time to treat COPD (chronic obstructive pulmonary disease), but recent studies have shown that it also has value to asthmatics. It can be added to existing therapies such as inhaled corticosteroids and inhaled bronchodilators, and seems to have a synergistic effect with the latter.

Slow dosage start more prudent?

Slow dosage start more prudent?

Questioning whether the starting dosage of a medication might influence the likelihood of hypersensitivity reactions, research scientists at the Medical University in New Zealand conducted a study using a time-honored therapy for gout.

Unfortunately this medication, Allopurinol, has a predilection to cause hypersensitivity reactions that can be troublesome because, in addition to an allergic skin rash, there also may be inflammation of the liver and kidneys.

The study was simple, comparing two groups starting Allopurinol. One group started with the usual full dose and maintained that dose; the other with half the usual dose. This dose was maintained for several months and only then was gradually increased to full strength.

Fifty-four patients developed drug allergy and almost all of them were among the full-dose starters. The scientists editorialized that they understood why full-dose starting is the usual approach as both the patient suffering the gout and the physician treating it want as speedy improvement as possible. But perhaps slow, gradual – and therefore safe – improvement is the better route.

Anaphylaxis care in pregnancy: New guidance published

Anaphylaxis care in pregnancy: New guidance published

 Anaphylaxis in pregnancy – a condition that poses risks for both the mother and the fetus – now has published guidelines, thanks to work done at the University of California in San Diego and the Kaiser Permanente Medical Center. Guidelines previously did not exist.  The authors point out that just as the general incidence of anaphylaxis is increasing, it is also increasing in pregnant women.

During the three trimesters of pregnancy the causes of anaphylaxis are the same as in the general population. In order of decreasing frequency these are: foods, stinging insects, medications, biologic agents (X-ray dyes) and latex. At the time of labor and delivery the causes shift. Again in the order of decreasing frequency they are: antibiotics, latex, neuromuscular blockers (used as part of anesthesia), oxytosin (used to stimulate contractions of the uterus), local anesthetics and transfusion of blood or blood products.

The symptoms of anaphylaxis in pregnancy are the same as in non-pregnant women, with a few caveats, and include itching, rash, swelling, throat constriction, wheezing, nausea, vomiting, diarrhea, tachycardia and low blood pressure. Symptoms somewhat unique to pregnancy include severe vulvar and vaginal itching, low back pain and premature labor contractions.

Treatment of anaphylaxis in pregnancy is the same as for non-pregnant women with some special considerations. Adrenalin (epinephrine) is still the mainstay of therapy. It is critical to give enough adrenalin to maintain the mother’s systolic blood pressure above 90 (and thereby the fetal blood flow).

IV fluids are used as in all people with anaphylaxis, as is oxygen – except in pregnant patients high levels, even 100 percent oxygen, are recommended. Recumbency is part of treatment of all anaphylaxis, but it is best for the pregnant woman lie on her left side so as to better ensure uterine blood flow.

Finally, if the anaphylaxis is protracted or severe, emergency C-section delivery of the infant is indicated.

Dear Doc: Wise to give MMR vaccine if child has allergy to eggs?

Dear Doc: Wise to give MMR vaccine if child has allergy to eggs?

 Dear Dr. K.: My daughter is allergic to eggs. They cause her to have hives. Should we avoid the MMR (measles-mumps-rubella – formerly known as German measles) shot?

The old answer to your question is a qualified “no.” The new answer is an unqualified “no.” But, let me explain.

Three primary vaccines exist that are produced using egg embryo fibroblasts. Because of this milieu, there is some – at least theoretical – potential for the vaccines to elicit an allergy in a person with egg allergy. The three are MMR, flu and yellow-fever vaccines. Of these, the MMR has the least amount of egg binders/fillers (technically excipients).

Prior to a fairly recent study done at Duke University in cooperation with Johns Hopkins, children with egg allergy were treated in several ways: In some cases, the administration of the MMR was delayed until the egg allergy and/or the allergy testing to egg diminished; in other cases, the children were tested with the allergy vaccine itself. If the test was positive, the vaccine administration was delayed until the test was negative. If the vaccine test was negative, then the MMR was given.

The Duke/Johns Hopkins study looked at a large group of children with a clinical history and skin-test confirmation of egg allergy. Testing for allergy to the MMR vaccine was positive in some and negative in others. All the children in this study were given the MMR vaccine; none had an allergic reaction. Therefore, based on this study, your daughter should go ahead and get the MMR shot.