In the past, positive blood and skin tests would often be mistaken for a food allergy because they would indicate the presence of immunoglobulin E antibodies, but it is important to remember that these are typically higher in patients with atopic dermatitis, according to a speaker at the 69th Annual American Academy of Dermatology Meeting conducted in New Orleans this week. “Those antibodies are not diagnostic, and the only way to diagnose food allergy is with a strong history of reactions or a challenge,” Jon M. Hanifin, MD, of Oregon Health & Science University, said in a press release. “This is done in a doctor’s office, using small increments of the food in question and increasing the amount until an allergic reaction occurs or does not occur. Usually a parent can pinpoint if a child has a true food allergy because the allergic reaction will appear so quickly with lip swelling or hives, quite distinct from simply food intolerance.”
Between 6% and 10% of children have atopic dermatitis, and about one-third of these children have food allergy. Recent research examining the genetic basis of atopic dermatitis has shown that this chronic skin condition is likely related to a defect in the epidermal barrier, which allows irritants, microbes and allergens (such as food) to penetrate the skin and cause adverse reactions. Because the skin barrier in patients with atopic dermatitis is compromised and open to absorb proteins, it allows sensitization to certain foods, leading to a positive skin or blood test.
New guidelines recently issued by the National Institute of Allergy and Infectious Diseases established a protocol for the proper evaluation and management of food allergy. The guidelines recommend that children who are younger than aged 5 years with moderate to severe atopic dermatitis be considered for food allergy evaluation if they have persistent atopic dermatitis despite optimized management or if the child has a reliable history of an immediate reaction after eating a specific food.
Hanifin said research is also ongoing into whether withholding foods is leading to more allergies than an unrestricted diet in young children. This may provide future insight in potential ways to prevent food allergies. He said children in Israel seldom get peanut allergy, which may potentially be attributed to the use of peanut proteins in pacifiers in that country. In the United States and Europe, where peanut allergies are more common, infants are not usually exposed to this food until they are toddlers – the time when most peanut allergies are noticed.
“There is some thinking that withholding foods might actually be causing more allergies, and that an unrestricted diet may help tolerize babies to foods that could potentially cause a problem later in life,” Hanifin said. “Ongoing studies in this country using oral immunotherapy appear promising, and physicians hope that we may discover how to prevent food allergies in the future while continuing to provide successful treatment for children with atopic dermatitis.”
Source: Hanifin J. Food allergy and dermatology. Presented at: The American Academy of Dermatology 69th Annual Meeting; Feb. 4-8, 2011; New Orleans
Having psoriasis appears to double the risk that a person will also have a dangerous clustering of risk factors for heart disease and diabetes known as metabolic syndrome, a new study shows. Previous research has found patients with psoriasis to be at higher risk for getting diabetes and high blood pressure, but the new study, which is in the Archives of Dermatology, is one of the first to document the broader complement of cardiovascular risks associated with the disease.
“It is more than skin deep,” says Abrar Qureshi, MD, MPH, co-author of the paper and vice chairman of the department of dermatology at Brigham and Women's Hospital in Boston. “We like to tell patients that psoriasis is a systemic disease. The risk for metabolic syndrome is high.”
Psoriasis is an autoimmune disease in which the body overproduces skin cells, causing a thick, scaly, red rash to appear on the palms, soles of the feet, elbows, scalp, or lower back. It is thought to be one manifestation of chronic, body-wide inflammation. Metabolic syndrome is defined as having at least three of the following risk factors for heart disease and diabetes: high blood pressure, too much belly fat, high fasting blood sugar, low levels of HDL “good” cholesterol, and high levels of bad blood fats called triglycerides. Studies have shown that having metabolic syndrome dramatically increases the risk of heart attacks, strokes, peripheral vascular disease, and type 2 diabetes.
Researchers say it's difficult to know which of the two might be driving the other. “There's evidence on both sides of the fence,” says lead study author Thorvardur Jon Löve, MD, of Landspitali University Hospital in Reykjavik, Iceland. “There's evidence that obesity drives the development of psoriasis. There's also evidence that inflammation drives some components of insulin resistance. It's a real chicken and egg problem at this point.”
Metabolic Syndrome and Psoriasis
The new study used blood test results from nearly 2,500 people who participated in the government-sponsored National Health and Nutrition Examination Survey between 2003 and 2006. None had previously been diagnosed with diabetes. Among study participants who said that a doctor had diagnosed them with psoriasis, 40% had metabolic syndrome, compared to just 23% of those who did not have psoriasis.
The association was particularly strong in women. Nearly half of women with psoriasis had metabolic syndrome, compared to just one in 5 women without psoriasis. In contrast, psoriasis appeared to raise a man's risk of having metabolic syndrome by only about 4%. “When you get this constellation of factors together, the risk is higher than the sum of the individual factors,” Löve says. “Visit your primary care physician and bring this up.”
Writing in an editorial in the US journal Archives of Neurology, Marian Evatt, assistant professor of neurology at Emory University School of Medicine, says that health authorities should consider raising the target vitamin D level. “At this point, 30 nanograms per millilitre of blood or more appears optimal for bone health in humans. “However, researchers don't yet know what level is optimal for brain health or at what point vitamin D becomes toxic for humans, and this is a topic that deserves close examination.”
Dr Kieran Breen, director of research at Parkinson's UK, said: “The study provides further clues about the potential environmental factors that may influence or protect against the progression of Parkinson's. “A balanced healthy diet should provide the recommended levels of vitamin D. “Further research is required to find out whether taking a dietary supplement, or increased exposure to sunlight, may have an effect on Parkinson's, and at what stage these would be most beneficial.”
Everyone gets the odd spot, but longer-term skin conditions can affect your level of self-confidence, especially if they are on your face. If you are suffering from acne or dry skin, don't worry. There are lots of easy treatments around that can help. Seeing a dietitian like Nastaran to improve your diet may also help with Skin Conditions.
Most people get spots, and they do always seem to break out when you really don't want them to. They're caused by your glands producing too much sebum – a substance that your body produces naturally to stop your hair drying out. Too much sebum makes your skin oily and causes spots.
Spots usually go away, but there are some things you can do to make them disappear a bit quicker:
- wash with an anti-bacterial face wash, instead of soap or shower gel, until the spots have gone
- don't squeeze them, as this can spread the infection and cause more spot outbreaks
- drinking a couple of pints of water a day can help
If your spots don't seem to be clearing up, you may be suffering from acne. Acne can be a more serious condition, so you should make an appointment with your doctor who can give you a check-up.
Acne is different from getting a few spots. It can appear on your back, shoulders and chest as well as your face and can sometimes be painful. Whether or not you suffer from acne doesn't depend on your level of personal hygiene; it can sometimes run in the family or it can be caused by high levels of stress.
Some people can get relatively mild forms of acne, where outbreaks are months apart. Others can get quite serious forms of the condition that can lead to scars. Although some sufferers get rid of acne by their early 20s, some people with very sensitive skin can still have the condition a number of years later.
Acne can also affect you emotionally. Sufferers of the condition can often get teased or bullied in school or college. It can also affect someone's self-confidence or body image and can cause stress – which in turn can make acne outbreaks even more severe.
Although special face washes and creams can help some people, serious acne usually needs to be treated with specialist medical treatments. These treatments are only available with a prescription. Make an appointment to see your doctor who can diagnose how serious the acne is decide the best course of action. Your doctor will also be able to talk to you about how to deal with any emotional distress you've suffered.
Patches of dry skin can affect anyone, especially when the weather turns colder and the wind starts to gust. Dry skin can form anywhere, but it's most common on your face, as that's the area that exposed to the cold air.
Using a moisturiser can help, as can using a lip balm if your lips are chapped. If your dry skin lasts for a long time and is itchy or feels hot when you touch it, go and see your doctor. They may be able to prescribe special creams that help more serious forms of dry skin like eczema or dermatitis.
Teenage boys who shave may find that they get a rash on their chin or neck after shaving. Although it's not painful, you may find it becomes itchy and irritating.
Using moisturiser after you've finished shaving stops your skin from drying out. Using an aftershave that doesn't contain any alcohol can also help if you've got particularly sensitive skin.
Source: Directgov. Reproduced with permission.
In the survey, commissioned by Act Against Allergy, further impact on family life was revealed. As a direct result of having a child with CMA, half (49%) the respondents have missed work, over a third (38%) have argued with their partner and 39% said the lives of other children in the family have also been disrupted.1
These findings were no surprise to Natalie Hammond, from Hertfordshire, UK, whose son Joe was diagnosed with CMA when he was six months old. Joe was initially misdiagnosed and even underwent surgery for a twisted bowel before doctors finally discovered that CMA was the cause of his illness. Mrs. Hammond said: “It was heartbreaking and frightening seeing Joe so sick – he would vomit and had blood in his stools. We felt utterly powerless, and couldn't believe a simple food like milk could do this. It took a long time to get over this terrifying and stressful experience.”
Cows' milk is one of the European Union's 'big eight' allergy-inducing foods alongside gluten, eggs, fish, peanuts, soya, treenuts and shellfish. More serious than lactose intolerance, a true milk allergy presents in one or more of three organ systems:
– Gastrointestinal (vomiting, diarrhoea, abdominal cramps, bloating) – affecting 50-60% of those with CMA
– Skin (rashes, including eczema and atopic dermatitis) – 50-70%
– Respiratory (wheeze, cough, runny nose) – 20-30%3
For further information on cows' milk allergy, see: www.actagainstallergy.com
Food allergies, by some accounts, affect about 4 percent of adults and 5 percent of children under the age of 6 in the United States, though this study raises questions about the reliability of such figures.
Food allergies can cause a variety of problems, ranging from mild skin rashes or nausea to a life-threatening, whole-body reaction known as anaphylaxis. The allergies can also have serious effects on patients' social interactions, school and work attendance, family economics and overall quality of life. “It's a life-defining diagnosis in a way,” said Chafen.
The National Institute of Allergy and Infectious Diseases is working on new clinical practice guidelines and, as part of its efforts, enlisted Chafen and her colleagues to review the current evidence on food allergies.
The researchers started their work by sifting through thousands of scientific papers, published between 1988 and 2009, that focused on the four foods — milk, eggs, fish and peanut and tree nuts — responsible for more than half of all allergies. They ultimately reviewed 72 studies, including one meta-analysis on prevalence, 18 studies on diagnosis, 28 studies on management, and four meta-analyses and 21 additional studies on prevention.
When examining the literature, the researchers found there was no universal definition of “food allergy,” in spite of NIAID's defining it as an “adverse immune response” that is “distinct from other adverse responses” such as a food intolerance. In fact, 82 percent of the studies provided their own definition of food allergy.
“This validates the idea that there exists a great deal of complexity and confusion in the field of food allergy, even at the level of the medical literature,” said co-author Marc Riedl, MD, MS, section head of clinical immunology and allergy at UCLA.
Along the same lines, there was a lack of uniformity for criteria in making a diagnosis. The current gold standard is the food challenge, during which a physician gives a patient a sample of the suspected offending food, sometimes in capsule form, and then monitors for allergic reaction. However, this test requires specialized personnel, is expensive and has a risk of anaphylaxis. Office-based tests were used to diagnose many patients; these include a skin-prick test, during which a dilute extract of the potential allergen is placed on the skin, and a blood test that determines the presence of food-specific allergic antibodies known as IgE.
As the researchers discuss in their paper, the concern with the latter two tests is that they're not definitive: Patients with non-specific symptoms, such as a rash or digestive troubles, and positive skin-prick or blood tests actually have less than a 50 percent chance of having a food allergy. In order to make a proper diagnosis, they pointed out, physicians need to evaluate the data within the context of a patient's history and have a great understanding of symptoms consistent with true food allergy.
What this means, then, is there is a potential for the overdiagnosis of food allergy.
“I frequently see patients in my clinical practice who have food intolerance, but have previously had inadequate or inappropriate evaluation and been told they have a 'food allergy',” said Riedl. “This causes a great deal of unnecessary anxiety and concern for the patient.”
Previous studies have tried to determine whether the skin-prick or blood test is superior over the other, but in reviewing the evidence, Chafen and her colleagues found “no statistical superiority in either test.” They also found generally inconclusive results from 10 previous studies in which the tests were combined, in an effort to improve diagnostic accuracy.
“I was very surprised,” said Chafen. “I'm a general internist and I thought diagnostic strategies were more-studied.”
In terms of treatment, Chafen said expert opinion is that an elimination diet — having the patient stop consuming the food that causes the allergic reaction — is the most common. Although the approach is a common-sense one (“If a patient breaks out in hives repeatedly after drinking milk, it's your instinct as a physician to say, 'Don't drink milk,'” Chafen said), the researchers found the treatment hasn't been well-studied.
It would be unethical to conduct controlled studies of elimination diets for patients with serious, life-threatening allergic reactions, but as pointed out in the paper, there are few studies of this approach on patients with relatively minor symptoms.
“In these instances, the benefits of an elimination diet are uncertain based on published evidence and potential benefits need to be weighed against the potential nutritional risks of such a diet, particularly in children,” the researchers wrote.
Chafen and her colleagues also found that immunotherapy, a treatment in which the body's immune system is altered by administering increasing doses of the allergen over time, appeared to be effective at eliminating symptoms in the short term. Immunotherapy isn't a licensed method for allergy treatment, but the researchers urged more study on its long-term effect and safety.
In all, the researchers concluded, the food-allergy field is in need of uniformity in the criteria for what constitutes an allergy and a set of evidence-based guidelines upon which to make this diagnosis. NIAID, which put together an expert panel and has reviewed the group's analysis, is planning to finalize such guidelines later this summer.
As for Chafen, who sees patients with potential food allergies, these findings have encouraged her to rely more on specialists to help clinch a diagnosis. “People need to be seen by someone with a deep understanding of diagnostic tests and criteria,” she said. “The distinction between food intolerance and food allergy is really important.”
The study was funded by NIAID. Other Stanford authors on the study are Dena Bravata, MD, a PCOR affiliate; and Vandana Sundaram, MPH, assistant director of research for CHP/PCOR. Paul Shekelle, MD, PhD, with the RAND Corp.'s Southern California Evidence-Based Practice Center and the West Los Angeles VA Medical Center, is the senior author.
Some people may be at risk of not getting enough vitamin D because they don’t get enough in their diet or because they have more limited sun exposure which reduces the amount of vitamin D their bodies make. Those at risk include:
Breastfed infants require 400 IU vitamin D per day from birth. Because breast milk is naturally low in vitamin D and infants are not usually exposed to the sun, a vitamin D supplement of 400 IU is recommended. Healthy term infants fed infant formula do not require a vitamin D supplement as it is already added to the formula.
- Pregnant women should consume vitamin D from food (for example, from a least 3 glasses of milk der day) or supplements (usually 200-400 IU is provided in a supplement) to ensure the baby is born with optimal vitamin D in their body. If a supplement is taken, be sure not to exceed 2000 IU vitamin D per day.
- Adults over 50 years may not prodce vitamin D in skin as well as when they were younger. It is recommended that adults (men and women) over 50 years take a supplement of 400 IU / day.
- People with skin darkly pigmented with melanin are less able to make vitamin D from exposure to sunlight. Since many people with darker skin colour also avoid vitamin D fortified milk due to lactose intolerance, their dietary intake of the vitamin may be low, so extra vitamin D, such as the amount typically found in a general multivitamin-mineral supplement (200-400 IU) would be a good idea.
- People with limited sun exposure sun exposure is limited due to mostly living or working indoors, wearing clothing such as long robes and head coverings, then it is wise to carefully choose vitamin D rich foods (see above) or to take a vitamin D supplement, such as the amount typically found in a general multivitamin-mineral supplement (200-400 IU).
Some medical conditions such as Crohn's disease, cystic fibrosis, celiac disease, surgical removal of part of the stomach or intestines, and some forms of liver disease, interfere with absorption of vitamin D. Being overweight and obese causes fat to stay stored in fat tissues and not be released into the blood, preventing vitamin D from being available to the body. If you have one of these conditions, check with your doctor to ask if a vitamin D supplement is needed.
Can I take too much vitamin D?
Yes. Too much vitamin D can be harmful. The total daily intake from food and supplements combined should not exceed 1000 IU for infants and young children and 2000 IU for adults.
The Bottom Line
Most people, except those in the risk groups noted above, can get enough vitamin D if they eat enough vitamin D rich foods (for example, milk, vitamin D fortified foods and some fatty fish) and if they engage in safe sun practices. If you are concerned about your vitamin D status, discuss the issue with Nastaran.
Source: Dietitians of Canada. Reproduced with Permission. Note: The Australian adequate intake is 200 IU however Nastaran recommends 400 IU as per the Canadian recommended intake.