Chronic obstructive mumps, also known as parotid ductitis and formerly known collectively with recurrent mumps as chronic suppurative mumps, is an inflammatory disease in which the parotid gland is repeatedly swollen and pus-filled due to various causes of obstruction of the parotid ducts. The etiology of chronic obstructive parotitis is mainly due to local causes. For example, when wisdom teeth erupt, the mucous membrane of the ducts is bitten and the scar heals causing narrowing of the ducts. Injury to the ductal orifice and buccal mucosa caused by poor denture restorations can also cause scarring, resulting in ductal stenosis. Rarely, it is caused by ductal calculi or foreign bodies. Foreign bodies include rice husks, rice grains, etc. The narrowing of the ducts or obstruction by foreign bodies leads to poor salivary drainage of the parotid gland, stagnation of saliva and retrograde infection, and distal duct dilatation. The pathology of the disease is characterized by dilatation of the dominant and branch ducts, ductal epithelium shedding, degeneration, ductal wall edema, periductal fibrous tissue hyperplasia and inflammatory cell infiltration, late atrophy and disappearance of the glandular vesicles, replacement by connective tissue and inflammatory cells, terminal duct hyperplasia, and tissue transformation. The diagnosis is mainly based on clinical manifestations and parotid imaging (1) Clinical manifestations: unilateral or bilateral onset, but unilateral is more common; patients often do not specify the time of onset, and are often seen for repeated episodes of parotid swelling, which are mostly associated with eating. The swelling is often associated with eating. It is accompanied by mild pain; after pressing the parotid gland, some salty fluid is felt to flow out from the ductal opening, followed by a feeling of relief; clinical examination of the parotid gland is mildly swollen, slightly tough, with redness and swelling at the mouth of the parotid duct, and cloudy fluid flows from the ductal opening when the gland is pressed; sometimes striated ducts can be palpated in the cheek. (2) Routine examination: Parotid gland imaging is routinely performed. In chronic obstructive parotitis, parotid angiography shows partial narrowing and dilatation of the dominant, interlobular, and interlobular ducts of the parotid gland, with salami-like changes. In some cases, only the dominant duct and larger branch ducts are visible, with only a small amount of contrast in the glandular area. In some cases, only the dominant duct and larger branch ducts are visible, with only a little contrast in the glandular area. (1) Adult recurrent parotitis has a history of recurrent episodes in childhood. In addition to the slightly dilated dominant ducts of retrograde infection, adult recurrent parotitis parotid angiography shows only scattered dotted and globular dilatation of the terminal ducts, with no changes in the interlobular and interlobular ducts, whereas obstructive parotitis is characterized by irregular dilatation of the ductal system. (2) Secondary infections of Schegren’s syndrome may also have a history of recurrent swelling and pus in the parotid gland. The differences are: the onset of the disease is usually in middle-aged women; there are symptoms of dry mouth and dry eyes; parotid imaging shows dotted and globular dilatation of the terminal ducts and characteristic changes in the dominant ducts; histopathological manifestations are significantly different; and several laboratory and immunological tests may be abnormal.