Sensitivity to gluten with negative celiac disease testing or non-celiac sensitivity to gluten is a recently recognized problem with clinical manifestations that are superimposed with those of fibromyalgia, chronic fatigue and irritable bowel syndrome.

We present the case of a 40-year-old woman who came to the clinic with a 7-year history of generalized pain and chronic fatigue. She had been diagnosed with fibromyalgia by several rheumatologists and complied with the 1990 American College or Rheumatology criteria. She also presented chronic fatigue syndrome criteria. She had concentration and memory problems, «foggy mind», and intermittent diarrhea. The severity of the affection led to limitation in her daily activities which limited her to bed rest in spite of several visits to specialists in rheumatology, gastroenterology and alternative medicine/homeopathy. In addition to the typical symptoms of fibromyalgia, chronic fatigue and intermittent diarrhea, she had oral ulcers, autoimmune hypothyroidism and a history of iron deficiency. She had undergone multiple studies with normal findings, including anti-transglutaminase IgA antibodies to rule out celiac disease.

We suspected sensitivity to gluten and more studies were performed. Laboratory studies showed iron deficiency and low vitamin D levels. On a screening test for anti-transglutaminase and anti-deaminated gliadin peptide antibodies, both IgG and IgA were negative. HLA typing showed the presence of DQ2 (DQA1*05 DQB1*02). Gastroscopy showed small erythematous lesions on the duodenal bulb. Duodenal biopsies showed normal villi structure and lymphocytic duodenitis with apical redistribution, 28 CD3 lymphocytes for every 100 enterocytes (stage I Marsh lesions). Urease testing for Helicobacter pylori was positive. Celiac disease was ruled out due to the absence of specific antibodies or intestinal villi atrophy, though we still suspected sensitivity to gluten. A gluten-free diet was recommended without treating the infection by Helicobacter pylori.

Six months after starting the diet there was a marked improvement in all of the symptoms, with remission of the oral ulcers; the patient had gone back to work after a long disability period. When she consumed small amounts of gluten she experimented a relapse of all of the symptoms. Iron and mineral supplementation was carried out. 2 years after she started the diet there was remission of fibromyalgia, she continued working and practiced sports. During that time her daughter had been diagnosed with celiac disease, presented positive anti-transglutaminase antibodies and villi atrophy on the duodenal biopsy.

The existence of non-celiac gluten sensitivity is recognized based on the observation of patients whose symptoms respond to a gluten-free diet but have negative celiac disease tests.1–4 Lymphocytic duodenitis is a characteristic of celiac disease that may present without villi atrophy in non-celiac gluten sensitivity, although it is not a specific finding as it may have other causes, such as Helicobacter pylori.5,6 When, as in this case, a patient with gluten sensitivity has an HLA susceptibility and Marsh 1 enteropathy, there is such a diagnostic proximity to celiac disease that the term of Marsh 1 celiac disease has been proposed.7 A gluten-free diet was attempted in this patient without treating Helicobacter because it was unlikely that treatment would improve the fibromyalgia.

Non-celiac gluten sensitivity has recently been described as a cause of fibromyalgia.8 This case reinforces this hypothesis due to the characteristic clinical response, a relapse after gluten consumption, the HLA typing, the presence of lymphocytic duodenitis in the duodenal biopsy and the latter diagnosis of celiac disease in her daughter.