Research Roundup: Allergic to Chalk, Gluten-Free Diet for IBS, & More!
The latest medical news for people with allergies and food sensitivities
Allergic to Chalk
Classroom chalk containing casein can trigger respiratory symptoms in milk-allergic children, say researchers from the Hospital Marina Baixa in Spain. They studied a group of 12 milk-allergic children and found that all were sensitized to the chalk (allergy testing was positive). In four of the children, the chalk dust triggered wheezing, coughing and sneezing. Symptoms improved when the chalk was switched to a brand that didn’t contain casein.
Casein is a milk protein that can be present in non-food items, such as paper, glue and dustless or low-powder chalk, which is preferred by many schools because it keeps hands and classrooms cleaner. However, low-powder chalk still releases casein particles into the air, say researchers. And even though airborne milk proteins are not ingested (the usual route of exposure in food allergy), they may still cause symptoms when they’re inhaled, they write.
If your child is sneezing and wheezing at school, the American College of Allergy, Asthma and Immunology (ACAAI) recommends seeing a board certified allergist for proper diagnosis and treatment.
The study was published in May in the Annals of Allergy, Asthma and Immunology, the scientific journal of the ACAAI.
Gluten-Free Diet for IBS
The gluten-free diet may benefit some who have irritable bowel syndrome, new research suggests. IBS sufferers with diarrhea-predominant IBS had fewer bowel movements per day on the gluten-free diet compared to those on a gluten-containing diet. The effect was greatest among participants who also had genetic markers associated with celiac disease, DQ2 and/or DQ8. However, none of the participants had celiac disease or had previously followed a gluten-free diet. They were assigned at random to the gluten-free or a gluten-containing diet for four weeks.
Although more research is needed, this study’s finding supports the theory that gluten may be an IBS trigger and that the gluten-free diet can help. The study was conducted at the Mayo Clinic and published in May in Gastroenterology.
In other research relating to IBS, a team from NorthShore University Medical Center in Evanston, Illinois, says IBS may raise the risk of osteoporosis. According to this study, those with IBS had four times the risk of osteoporosis and twice the risk of sustaining a fracture compared to those without IBS. The risk was similar for both men and women.
The NorthShore researchers analyzed a large database of hospital emergency room visits that included some 317,000 patients with IBS, of whom 17,000 also had osteoporosis. They investigated a link between IBS and osteoporosis because certain chronic gastrointestinal disorders, namely, inflammatory bowel disease and untreated celiac disease, are known to raise the risk for bone thinning. The National Osteoporosis Society calls the study’s findings intriguing but too preliminary to warrant screening for osteoporosis in individuals with IBS.
The study was published in April in Osteoporosis International.
Gluten Antibodies in Autism
The gluten-free diet has become increasingly popular in the autistic community. Now a new study conducted at Columbia University Medical Center in New York found that a subset of autistic children show heightened immune activity to gluten. Researchers studied 37 children with autism and 103 others without autism.
Twenty percent of autistic children, especially those with gastrointestinal symptoms, had significantly elevated levels of gluten antibodies compared to those without autism. There was no link to celiac disease, however. Rates of celiac-specific antibodies and the genetic markers for celiac disease were similar across the groups.
The significance of the gluten antibodies is unclear. It doesn’t necessarily indicate sensitivity to gluten or any disease-causing role for the antibodies in the context of autism, said Armin Alaedini, PhD, the study’s lead investigator, in a press release. He then added that the findings point to immunologic and/or intestinal permeability abnormalities in these children.
It’s possible a better understanding of the immune response to gluten may offer clues about autism or help identify a subset of children with autism who would positively respond to dietary treatment.
The study was published in June in PLoSONE.
Egg-Free Flu Shot
A new seasonal flu vaccine received FDA approval earlier this year and now a CDC advisory panel has recommended it for adults with egg allergy this flu season. The new shot, called Flublok, is different from other influenza vaccines because it doesn’t use eggs in its manufacturing process. Flublok is recommended for those with egg allergy of any severity but so far it’s only FDA approved for adults ages 18 to 49.
According to the American Academy of Allergy, Asthma and Immunology, the risk of an allergic reaction to egg in the standard flu shot is low but those with a history of serious reaction to eggs should have the vaccine administered in an allergist’s office.
For more information about Flublok, talk to your doctor and visit cdc.gov/flu/protect/vaccine/qa_flublok-vaccine.
Anemia Signals Trouble
Anemia, not diarrhea, points to more severe intestinal damage in those with celiac disease, say researchers from the Celiac Disease Center at Columbia University College of Physicians and Surgeons in New York. They compared the degree of villous atrophy with celiac blood tests in 727 people diagnosed between 1990 and 2011. They also looked at the bone mass density. Results revealed that celiacs with anemia were more than twice as likely to have severe villous atrophy and a low bone mass density at diagnosis compared to those whose primary symptom was diarrhea. Anemia was also associated with higher levels of the celiac-specific antibody, anti-tissue transglutaminase.
Diarrhea has long been considered the classic symptom of celiac disease. However, doctors are increasingly recognizing atypical and outside-the-gut symptoms like anemia as the norm in celiac disease.
The study was published in June in Clinical Gastroenterology and Hepatology.
Ticks and Meat Allergy
Researchers at the University of Virginia now have more evidence that certain tick bites are behind an unusual allergy to meat. In 2009, they studied 24 adults who developed hives and even anaphylaxis after eating beef, pork or lamb. Most of the adults reported having had a tick bite just before the onset of symptoms and all 24 of them (who’d previously eaten meat without incident) had antibodies to alpha-gal, a sugar found in both red meat and tick saliva.
Now these same researchers have identified 45 suspected cases in children. Like the adults, most of the children experienced a “persistently red and itchy” tick bite before developing symptoms, which included hives and trouble breathing. Almost half of the reactions were severe enough to send the children to the emergency room.
Unlike most allergic reactions, which are immediate, reactions to alpha-gal are delayed, occurring three to six hours after eating red meat. This can make spotting the allergy particularly challenging, say researchers. They recommend testing for alpha-gal sensitivity in children with a history of unexplained or delayed allergic reactions, especially those youngsters who live in areas where the Lone Star tick is common. This type of tick has been implicated in the alpha-gal phenomenon.
The study was published in May in Pediatrics. For more about tick-induced meat allergy, go to LivingWithout.com and read “Ticked Off.”
Potential Celiac Disease
Individuals who have celiac antibodies but not intestinal damage (despite eating a regular, gluten-containing diet) may be labeled with “potential celiac.” Experts suspect that potential celiac disease can evolve into active celiac disease, with celiac’s hallmark flattening of the intestinal villi—but this path isn’t certain.
To shed light on this evolution, researchers from the University of Pavia in Italy looked back at all 187 patients diagnosed with potential celiac disease at their center between 1999 and 2011. The prevalence of potential celiac among all celiac-related cases was high, about 1 in every 4.4 patients. Some of the potential celiacs never developed active celiac during the study period. Their symptoms resolved even as they continued to eat a gluten-containing diet.
Interestingly, those with potential and active celiac had similar lab values, symptoms and average age of disease onset, leading researchers to speculate that potential celiac can only develop into active celiac (and not some other disease). However, this development doesn’t always take place. Researchers also say that potential celiac may actually be its own entity and not just an early form of active celiac disease.