Celiac Disease Atypical

Celiac disease is an immune-mediated enteropathy caused by dietary gluten in a genetically susceptible person, most often one carrying HLA-DQ2 or HLA-DQ8. Gluten exposure activates tissue transglutaminase–mediated immune injury in the small intestine. Intraepithelial lymphocytes increase, crypts become hyperplastic, and villi flatten. The damaged mucosa absorbs iron, folate, vitamin B12, calcium, vitamin D, and other nutrients less effectively. That mechanism explains why a patient may present with anemia or low bone density rather than diarrhea. Adults frequently have a non-classical presentation and may have neither diarrhea nor weight loss. Celiac disease can instead appear as persistent iron-deficiency anemia, premature osteoporosis or osteopenia, unexplained transaminase elevation, chronic fatigue, headaches, peripheral neuropathy, recurrent aphthous stomatitis, dental enamel defects, infertility, or recurrent miscarriage. Children may have short stature, delayed puberty, or irritability. Dermatitis herpetiformis is a particularly useful clinical clue: an intensely pruritic, symmetric papulovesicular eruption on the elbows, knees, or buttocks. Gastrointestinal symptoms may be absent. The rash is the cutaneous manifestation of gluten-sensitive disease, not a separate food allergy.