If milk, wheat, and egg allergy can cause rhinitis, they can also result in vaginitis, urethritis, and cystitis. The kidneys present a large filtering surface to blood contents and are vulnerable to damage by circulating immune complexes containing food allergens. The child's report of flank pain often imitates an attack of kidney infection or renal colic. Children with food allergy may have fever with flank pain and frequency of urination and are often invasively investigated and treated with no thought to a food antigen origin of their problem. Glomerulonephritis may sometimes be triggered by immune complexes containing food protein antigens.
Parents can use urine test sticks at home to monitor their child's urine everyday.
After dietetic therapy a significant reduction of urinary proteins was recorded present in 12 cases during the 6 months preceding the treatment, was markedly reduced or disappeared in 11. At post-treatment control biopsy mesangial and parietal deposits of immunoglobulins, complement C5 fraction and fibrinogen were significantly reduced. The nephrotic syndrome involves increased glomerular excretion of protein - Gabordi et al reported a 6 year old girl with gluten allergy expressed as celiac disease and dermatitis herpetiformis who developed nephrotic syndrome. Elimination of gluten grains resolved all three major manifestations of gluten allergy. Sandberg et al reported on 6 patients who experienced remission of nephrotic syndrome when milk was eliminated from their diet and exacerbation when it was reintroduced.