Ischemic Enteritis When the blood supply to a tissue is interrupted, a sequence of chemical events leads to cellular dysfunction, edema, and ultimately cell death. Tissue anoxia results in anaerobic…

Diseases Associated with Abnormal Deposits in the Tissues Hemochromatosis Hereditary hemochromatosis (HH), an autosomal recessive disease, causes 1 in 7,000 hospital deaths and 1 in 20,000 annual hospital admissions (628)….

Cystic Fibrosis Cystic fibrosis (CF) is an autosomal recessive disorder that affects 1 in 100,000 to 200,000 live births. CF results from mutations in the gene encoding the cystic fibrosis…

Small Intestinal Lesions Resembling Graft Versus Host Disease Changes similar to those found in GVHD sometimes occur in immunosuppressed or immunodeficient patients, without transplants or transfusions. The lesion affects any…

Immunodeficiency Diseases Patients with immunodeficiency syndromes often present with chronic diarrhea, malabsorption, and other intestinal abnormalities, as well as with the effects of the immunodeficiency, particularly infections. The immunodeficiency syndromes…

Graft Versus Host Disease GVHD is an immunologic disorder that results in severe gastrointestinal damage. It represents the response of immunocompetent donor cells to the histocompatibility antigens of the recipient….

Systemic Mastocytosis Systemic mastocytosis is characterized by mast cell proliferation in skin, bones, lymph nodes, and parenchymal organs. Patients usually present with classic dermatologic findings of urticaria pigmentosa. Typical symptoms…

Nutritional Disorders Severe nutritional deficiency can produce marked small intestinal abnormalities. The classic example is kwashiorkor. Malnutrition of this severity seldom occurs in developed countries, but less severe forms may…

Eosinophilic Diseases Food Allergies Up to 45% of the population report adverse reactions to food (572). Various enteric antigens play a role in the pathogenesis of conditions loosely termed food…

Granulomatous and Histiocytic Inflammatory Conditions Small intestinal granulomas form in many disorders (Table 6.15). The nature of the granulomas varies significantly from small macrophage collections that may or may not…