Less common disorders:S
互联网
908
佚名
DISEASE AND CAUSES | PATHOPHYSIOLOGY | SIGNS AND SYMPTOMS |
Sarcoidosis | ||
|
Organ dysfunction results from an accumulation of T lymphocytes, mononuclear phagocytes, and nonsecreting epithelial granulomas, which distort normal tissue architecture. |
|
Scabies | ||
|
Mite burrows superficially beneath stratum corneum depositing eggs that hatch, mature, and reinvade the skin. |
Occur from sensitization reaction against excreta that mites deposit
|
Schistosomiasis | ||
|
Infection follows contact by bathing with free swimming cercariae of the parasite, which penetrate the skin, migrate to intrahepatic portal circulation, and mature. Adult worms then lodge in venules of bladder or intestines. |
Depends on infection site and stage of disease.
In initial stage:
|
Shigellosis | ||
|
Shigella is orally ingested or transmitted by fecal-oral route. Invasion of colonic epithelial cells and cell-to-cell spread of infection results in characteristic mucosal ulcerations. |
In children:
|
Silicosis | ||
|
Alveolar macrophages engulf respirable particles of free silica, which causes cytotoxic enzymes to be released. This attracts other macrophages into the area and produces fibrous tissue in the lung parenchyma.
Note: Silicosis is associated with a high incidence of active tuberculosis. |
In simple nodular silicosis:
|
Sjogren's syndrome | ||
|
Lymphocytic infiltration of exocrine glands causes tissue damage that results in xerostomia and dry eyes. |
In xerostomia:
|
Sleep apnea | ||
|
In obstructive sleep apnea, airflow ceases due to upper airway narrowing and glottal obstruction as a result of obesity or congenital abnormalities of the upper airway.
When primary brain stem medullary failure occurs, patient may breathe insufficiently or not at all while asleep. |
In obstructive sleep apnea:
|
Spasmodic torticollis | ||
|
Rhythmic muscle spasms of sternocleidomastoid neck muscles possibly due to irritation of the nerve root. |
|
Spinal ischemia/infarction | ||
|
Major arterial branches that supply the spinal cord can become compressed or occluded, decreasing blood flow to the spinal cord, causing ischemia of cord and resulting in motor and sensory deficiencies. |
|
Sporotrichosis | ||
|
Inflammatory response includes both the clustering of neutrophils and a marked granulomatous response, with epithelioid cells and giant cells producing nodular erythematous primary lesions and secondary lesions along lymphatic channels in cutaneous lymphatic type.
In pulmonary sporotrichosis, inflammatory response produces pulmonary lesions and nodules. In disseminated sporotrichosis, multifocal lesions spread from skin or lungs. |
In cutaneous or lymphatic sporotrichosis:
|
Spurious polycythemia | ||
|
Concentration of RBCs in the circulating blood increases due to loss of blood plasma. |
No specific symptoms; following may present:
|
Stomatitis | ||
|
Inflammation of the cells of the oral mucosa, buccal mucosa, lips and palate with resulting ulcers. |
|
Strabismus | ||
|
In paralytic (nonconcomitant) strabismus, paralysis of one or more ocular muscles may be due to oculomotor nerve lesion.
In nonparalytic (concomitant) strabismus, unequal ocular muscle tone is due to supranuclear abnormality within the CNS. |
|