Population-based screening studies have shown celiac disease to be one of the most common chronic gastrointestinal diseases. Nevertheless, because of the diverse clinical presentation, the great majority of patients remain unrecognized. Particularly difficult to identify are the multifaceted extraintestinal symptoms that may appear at variable ages. Although the pathogenesis and long-term outcome of these manifestations are still poorly established, there is some evidence that unrecognized celiac disease predisposes to severe complications if not diagnosed and prevented with an early-initiated gluten-free diet. Therefore, it is of utmost importance that physicians of different disciplines learn to recognize celiac disease in individuals with non-gastrointestinal symptoms. In the future, more studies are needed to clarify the factors affecting development and prognosis of the extraintestinal manifestations.

Summary: Background: The best‐known symptoms of coeliac disease are related to the gastrointestinal tract, but the disease may also present with various systemic manifestations outside the intestine. Some of these consequences may remain permanent in undiagnosed individuals or if the diagnostic delay is prolonged. However, for many of the systemic manifestations, the scientific evidence remains scant and contradictory.Aims and Methods: We conducted a narrative review of the most thoroughly studied and clinically relevant systemic consequences of coeliac disease, especially those that could be prevented or alleviated by early diagnosis. The review is intended particularly for physicians encountering these patients in daily clinical practice.Results: The possible systemic consequences of coeliac disease extend to multiple organ systems, the best studied of which are related to skeletal, reproductive, cardiovascular and neurological systems. Furthermore, the disease is associated with an elevated risk of psychiatric comorbidities, non‐Hodgkin lymphomas and intestinal adenocarcinoma.Conclusions: The various systemic consequences of coeliac disease play a significant role in the overall health of patients. Early diagnosis and treatment with a gluten‐free diet appear to be beneficial for most, but not all of these conditions. The possible negative metabolic and psychosocial effects of the diet should be acknowledged during follow‐up.

Impaired growth is a well-known complication in celiac disease, but factors associated with it are poorly known. We investigated this issue in a large cohort of children. 530 children with biopsy-proven celiac disease were included. The participants were divided into two groups on the basis of the presence (n = 182) or absence (n = 348) of growth disturbance at diagnosis. Histological, serological and clinical characteristics were compared between children with growth failure and those with normal growth. Further, patients with growth failure as the sole clinical presentation were compared to those with poor growth and concomitant other symptoms. Children with growth failure were younger (p < 0.001) and had lower hemoglobin (p = 0.016) and higher celiac antibody (p < 0.001), alanine aminotransferase (p = 0.035) and thyroid-stimulating hormone values (p = 0.013) than those with normal growth. Significantly associated with growth failure at diagnosis were age <3 years (OR 4.3 (95 % CI 2.5-7.5) vs older age), diagnosis before the year 2000 and in 2000–09 (OR 3.1 (1.8-5.4) and OR 1.8 (1.1-2.8) vs diagnosis in 2010–2013), presence of total and subtotal villous atrophy (OR 4.2 (2.5-7.0) and OR 2.0 (1.3-3.2) vs partial atrophy), severe symptoms (OR 3.4 (1.8-6.7) vs mild symptoms) and vomiting (OR 3.1 (1.5-6.3). The presence of abdominal pain reduced the risk (OR 0.5 (0.3-0.7)), while there was no effect of gender, diarrhea, constipation, other chronic diseases and celiac disease in the family. Children evincing poor growth as the sole clinical presentation were older (p < 0.001) and had higher hemoglobin (P < 0.001) and total iron (p = 0.010) values and lower TG2ab values (p = 0.009) than those with growth disturbance and other symptoms. In particular young age and severe clinical and histological presentation were associated with growth disturbance at celiac disease diagnosis. Children with only poor growth are markedly different from those with other concomitant symptoms, suggesting different pathogenic mechanisms.

Celiac disease is one of the most common food-related chronic disorders in children. Unfortunately, this multifaceted disease is challenging to recognize and remains markedly underdiagnosed. Screening of either known at-risk groups or even the whole population could increase the suboptimal diagnostic yield substantially. Many recent guidelines recommend screening of at least selected risk groups, but more wide-scale screening remains controversial. The increasing prevalence of celiac disease and the development of autoantibody assays have also led to a gradual shift in the diagnostics towards less invasive serology-based criteria in a subgroup of symptomatic children. The main open questions concern whether these criteria are applicable to all countries and clinical settings, as well as to adult patients. On the other hand, widening screening and the mistaken practice of initiating a gluten-free diet before the appropriate exclusion of celiac disease increase the number of borderline seropositive cases, which may also challenge the classical histopathological diagnostics. Sophisticated diagnostic methods and a deeper understanding of the natural history of early developing celiac disease may prove useful in these circumstances.

The prevalence and associated factors of daily life restrictions due to a gluten-free diet in adult celiac disease patients diagnosed in childhood are poorly known. We investigated these issues by collecting the medical data of 955 pediatric patients and sending questionnaires evaluating various health outcomes to the 559 patients who had reached adulthood. Of the 231 respondents, 46% reported everyday life restrictions caused by dietary treatment. Compared with those without restrictions, they more often had anemia at diagnosis (37% vs. 22%, p = 0.014), but the groups were comparable in other diagnostic features. In adulthood, patients with restrictions reported more overall symptoms (32% vs. 17%, p = 0.006), although the symptoms measured with the Gastrointestinal Symptom Rating Scale questionnaire were comparable. Despite strict dietary adherence in both groups, the experience of restrictions was associated with dietary challenges (34% vs. 9%, p < 0.001), health concerns (22% vs. 13%, p = 0.050), and lower vitality scores in the Psychological General Well-Being questionnaire. The groups did not differ in their current age, socioeconomic status, family history of celiac disease, general health or health-related lifestyle, the presence of co-morbidities, or regular follow up. Our results encourage healthcare professionals to discuss the possible health concerns and dietary challenges with patients to avoid unnecessary daily life restrictions, especially when young patients start to take responsibility for their treatment.