Nilda is an 18-year-old college freshman who has returned home for her winter break from school and is brought in by her parents to see her pediatrician, Dr. O’Shea, because of apparent weight loss since the summer, as well as a change in eating habits and various physical complaints. According to her parents, Nilda appears much thinner than she did in August when she left for school. She is eating very little at mealtimes, citing that she feels “full.” While at school, she would often complain to her parents that she was feeling “sick to my stomach.” Nilda admits to Dr. O’Shea that she has been eating less, explaining that she feels “bloated” all the time, so—even though she can often feel hungry—she becomes quickly uncomfortable when eating and sometimes will skip meals because of this. She has loose stools a few times a week. She also complains of fatigue, and though her grades had been holding up through midterms, she is worried about how she did on finals, as she felt she “could not concentrate.” She admits to reading a lot about “food allergies” online and wonders if she needs to stop eating gluten—“like, bread and cookies and stuff.” She is not able to clarify whether there are particular foods that make her feel worse, but she says that recently, she has been mostly sticking to eating green apples, “light” yogurt, and rice. She knows she has lost weight and tells Dr. O’Brien, “I’m sure I could use to lose some weight—I always feel like my gut is sticking out.” She reports that she is happy in school and that she has made a few good friends, but she is worried that college is “just not for me,” stating that she is afraid she will not be able to keep up the kinds of grades she got in high school. On review of systems, she reports that she went to the dentist last week and was found to have two cavities, her first cavities in her adult teeth.

Dr. O’Brien has been Nilda’s doctor since infancy. Nilda was a generally healthy child, though began having frequent doctor’s visits around age 8 through puberty, with vague abdominal symptoms which tended to correlate with return to school after vacations and other stressful events. Nilda saw the school counselor for a period of time during those years to work on her “anxieties.” At age 14, Nilda’s parents brought her in because she had begun eating less and seemed “weak and tired” all the time. Her medical evaluation at the time had been normal, and she was evaluated by a therapist for a possible eating disorder. She began eating more normally after several weeks in therapy, and this problem did not recur.

On examination, Nilda is 5′6″ and 120 lb (BMI 19.4; her weight in August had been 128 lb, BMI 20.7). Her vital signs are normal. Her abdomen is soft, but she complains of mild right upper quadrant tenderness on palpation. Her examination is otherwise unremarkable.

No clear psychiatric diagnosis at this time.

Rule out:
Cases like Nilda are seen fairly frequently in primary care settings. A combination of food- and body-related concerns in the setting of changes in diet and life stressors can pose a clinical challenge, raising suspicion of a variety of medical and psychiatric disorders. It is essential that the clinician considers a broad differential list and pursues a judicious workup, without prematurely jumping to any conclusions.
Absolutely. New gastrointestinal complaints with correlation to certain foods may be related to a food intolerance disorder. Nilda is not able to give a very careful report of which foods seem most associated with her symptoms, but intolerances or allergies to foods such as dairy, wheat, and gluten should be considered. She mentions “gluten” and bread products, which may mean that she has noticed that these foods are more likely to cause her symptoms, even if she has not been monitoring closely enough to be able to state that more convincingly. Gluten-related disorders have received a lot of attention in recent years. They are likely best separated out into 3 distinct disorders: celiac disease (CD), gluten allergy (GA), and non-celiac gluten sensitivity (NCGS). Though a comprehensive review of the pathophysiology, diagnosis and management of these disorders goes beyond the scope of this chapter, a brief review follows. CD is an immune-mediated enteropathy in which ingestion of gluten (a protein found in wheat, barley and rye) triggers an inflammatory response affecting the small bowel mucosa, leading to gastrointestinal (GI) symptoms, such as bloating, diarrhea, and weight loss, and extra-gastrointestinal symptoms, including anemia, dermatitis, and dental enamel hypoplasia. The diagnosis can be made clinically and supported by detection of serum markers of anti-endomysium immunoglobulin A (EMA IgA) and anti-tissue transglutaminase immunoglobulin A (tTG-IgA) as well as small bowel biopsy demonstrating the classic findings of intraepithelial lymphocytosis, crypt hyperplasia, and villous atrophy. Patients with CD—which may be present in 1 % of the population and can vary in severity of symptoms and age of onset or detection—find improvement in their symptoms with elimination of gluten from their diets. CD should be suspected in patients with unexplained weight loss, anemia, a family history of CD, or a personal or family history of other autoimmune conditions, such as diabetes mellitus type 1, autoimmune thyroiditis, or psoriasis.

GA is an adaptive immune response to ingested gluten, triggering IgE-mediated histamine release. It may present similar to and, in combination with, wheat allergy. GA may present with GI symptoms similar to CD, in addition to typical systemic allergic responses involving the upper respiratory tract and skin. Elimination of gluten and wheat may be necessary in the management of this disorder, depending on the severity of the response.