A thyroid ultrasound may be done but characteristic findings vary depending on the phase of AST during which the patient is observed. In the early inflammatory phase of AST, when obvious abscess formation is not evident, the ultrasound may show a localized hypoechoic process with an obscure border and effacement between the thyroid and surrounding perithyroidal tissues[ 98 ]. During the acute inflammatory stage of AST, clear cut abscess formation is noted in the affected thyroidal tissue[ 98 ]. Perithyroidal unifocal hypoechoic space and effacement of the plane between the thyroid and perithyroid tissues have been noted to be specific signs of AST[ 98 ]. Alternatively, the application of sonoelastography may reveal very stiff lesions corresponding to the areas of the thyroid which are especially painful[ 99 ] during acute phases of the AST episode which soften significantly as the patient responds to treatment[ 99 ]. As the AST resolves with appropriate treatment, ultrasound images may demonstrate deformity of the gland characterized by atrophy of the affected lobe, air pockets in the thyroidal tissue and scarring of the perithyroidal tissues[ 98 ].
Poverty is a good indicator of the rate of infectious diarrhea in a population. This association does not stem from poverty itself, but rather from the conditions under which impoverished people live. The absence of certain resources compromises the ability of the poor to defend themselves against infectious diarrhea. "Poverty is associated with poor housing, crowding, dirt floors, lack of access to clean water or to sanitary disposal of fecal waste ( sanitation ), cohabitation with domestic animals that may carry human pathogens, and a lack of refrigerated storage for food, all of which increase the frequency of diarrhea... Poverty also restricts the ability to provide age-appropriate, nutritionally balanced diets or to modify diets when diarrhea develops so as to mitigate and repair nutrient losses. The impact is exacerbated by the lack of adequate, available, and affordable medical care." 
The differential diagnosis in patients with generalized lymphadenopathy includes sarcoidosis, multicentric Castleman disease, infection (eg, tuberculosis), and lymphoma or other malignancy. IgG4-related lymphadenopathy is distinguished from these conditions by the modest lymph node enlargement, histologic distinctions on biopsy, lack of constitutional features, and the usually striking clinical response to glucocorticoids [ 9 ]. Patients with bilateral hilar adenopathy may mimic sarcoidosis. (See "Evaluation of peripheral lymphadenopathy in adults" and "Clinical presentation and diagnosis of non-Hodgkin lymphoma" and "Epidemiology, pathologic features, and diagnosis of classical Hodgkin lymphoma" and 'Lung and pleural disease' below and "Multicentric Castleman's disease" .)