Infants and small children are particularly susceptible to eustachian tube problems since theirs are smaller in diameter and more horizontal. Obstruction of the eustachian tube leads first to fluid buildup and then, if bacteria start to grow, bacterial infection. Obstruction results from collapse of the tube (due to weak tissues holding the tube in place and/or an abnormal opening mechanism), blockage with mucus in response to allergy or irritation, or infection. The role of allergy as the major cause of chronic otitis media has been firmly established in the medical literature. Elimination of food allergens has been shown to produce a dramatic effect in the treatment of chronic otitis media in over 90 percent of children in some studies. Since it is usually not possible to determine the exact allergen during an acute attack, the most common allergenic foods should be eliminated from the diet: milk and dairy products, eggs, wheat, corn, oranges, and peanut butter. The diet should also eliminate concentrated simple carbohydrates (sugar, honey, dried fruit, concentrated fruit juice, etc.) since they inhibit the immune system. See low immunity and immune support. Low humidity often contributes to ear infections by causing nasal swelling and reduced ventilation of the eustachian tube, or it may dry the eustachian tube lining, which could lead to increased secretions and an inability to clear fluid. Increasing the humidity level with the help of a humidifier is an important goal in the treatment of ear infections. Eczema is an allergic disorder of the skin. Eczema is characterized by chronic itchy, inflamed skin. The skin tends to be very red and scaly. Scratching and rubbing lead to darkened and hardened areas of thickened skin with accentuated furrows, most phentermine commonly seen on the inside of the wrist and elbows, face, and the back of the knees. Food allergy is the most frequent cause of chronic eczema. Elimination of food allergy is the primary goal in dealing with eczema. Although any food can trigger eczema, milk, eggs, and peanuts appear to be the most common food allergens. In one study, these three foods accounted for roughly 81 percent of all cases of phentermine childhood eczema. For more information on dealing with food allergies, see food allergy. It is also important to avoid rough-textured clothing; wash clothing with mild soaps only and rinse thoroughly; and avoid exposure to chemical irritants and any other agents that might cause skin irritation. Fibrocystic breast disease (FBD), also known as cystic mastitis, is a benign breast condition associated with the presence of multiple cysts in the breast tissue. FBD is usually a component of premenstrual syndrome (PMS) and is considered a risk factor for breast cancer. It is not, however, as significant a factor as the classic breast cancer risk factors: family history, early onset of menstruation (menarche), and late or no first pregnancy.