Human health and medicine

Scapuloperoneal muscular dystrophy

Scapuloperoneal muscular dystrophy: rare genetic disorder with shoulder-girdle and distal leg weakness; genetically heterogeneous, including MYH7-related myopathy, FHL1 X-linked form, and TRPV4-related SPSMA; main differential FSHD.

Scapuloperoneal spinal muscular atrophy

Scapuloperoneal spinal muscular atrophy (SPSMA, neurogenic scapuloperoneal amyotrophy, New England type) is a rare autosomal dominant TRPV4-related motor neuron disease causing scapular and peroneal muscle atrophy, laryngeal palsy, and distal weakness.

Scar excision

Scar excision, also known as scar revision, is a surgical procedure that cuts out an existing scar and re-closes the wound to produce a finer, better-oriented scar.

Scarf osteotomy

The scarf osteotomy is a Z-shaped cut of the first metatarsal bone used to correct hallux valgus, or bunions, with greater correction power than the chevron cut.

Scarlet fever

Scarlet fever (scarlatina), toxin-mediated Streptococcus pyogenes infection of children 5-15, marked by sandpaper rash, strawberry tongue, and fever; treated with penicillin, no penicillin resistance reported.

Scarring alopecia

Scarring alopecia (cicatricial alopecia) is a group of inflammatory hair loss disorders, including lichen planopilaris, frontal fibrosing alopecia, and CCCA, that permanently destroy hair follicles and replace them with scar tissue.

SCCSS study

SCCSS (Swiss Childhood Cancer Survivor Study), launched 2007, NCT03297034: Swiss national cohort of 5-year childhood cancer survivors registered since 1976, with 4,135 baseline respondents, sibling controls, and studies of late effects.

Scedosporiosis

Scedosporiosis, a rare mold mycosis caused by Scedosporium apiospermum complex species (and related Lomentospora prolificans infection, lomentosporiosis), causing pneumonia, mycetoma, skin, bone, CNS, and disseminated disease, treated with voriconazole and surgery.

Schaaf-Yang syndrome

Schaaf-Yang syndrome (SYS, Chitayat-Hall syndrome, OMIM 615547) is a rare imprinted-gene neurodevelopmental disorder caused by truncating variants in the paternal MAGEL2 allele at 15q11.2, marked by neonatal hypotonia, joint contractures, intellectual disability, and autism, overlapping but distinct from Prader-Willi syndrome.

Schamberg disease

Schamberg disease (progressive pigmentary dermatosis) is the most common pigmented purpuric dermatosis, described by Jay Frank Schamberg in 1901: asymptomatic cayenne-pepper red-brown patches on the lower legs from T-cell capillaritis and hemosiderin deposition.

Schatzki ring

Schatzki ring, or lower esophageal mucosal ring (B ring), a thin mucosal narrowing at the gastroesophageal junction first described by Richard Schatzki in 1953; found in 6–14% of barium swallows and a common cause of intermittent solid-food dysphagia when under 13 mm.

Schedule for Affective Disorders and Schizophrenia

The Schedule for Affective Disorders and Schizophrenia (SADS) is a semi-structured diagnostic interview, published in 1978, used in psychiatric research to assess mood disorders and schizophrenia.

Oct 15, 2026

Schedules for Clinical Assessment in Neuropsychiatry

The Schedules for Clinical Assessment in Neuropsychiatry (SCAN) is a set of semi-structured clinical interview instruments developed by the World Health Organization to diagnose adult mental disorders.

Scheimpflug imaging

Scheimpflug imaging is an ophthalmic technique in which a tilted camera photographs slit cross-sections of the anterior eye, building a 3D corneal model used to detect keratoconus.

Scheimpflug tomography

Scheimpflug tomography is an ophthalmic imaging method in which a rotating camera captures cross-sections of the cornea, building a 3D model used mainly to detect keratoconus before refractive surgery.

Schema therapy

Schema therapy, developed by Jeffrey Young in the 1990s, is an integrative psychotherapy targeting early maladaptive schemas and modes through limited reparenting, imagery rescripting, and chair work, studied mainly for personality disorders.

Scheuermann's disease

Scheuermann's disease (Scheuermann's kyphosis, juvenile kyphosis): rigid adolescent hyperkyphosis defined by ≥5° anterior wedging of three consecutive vertebrae; treated with bracing or fusion surgery.

Schilbach-Rott syndrome

Schilbach-Rott syndrome (SRS, BRSS, OMIM 164220) is an extremely rare autosomal dominant disorder with ocular hypotelorism, blepharophimosis, cleft palate, and hypospadias in males, described in 18 individuals.

Schilder disease

Schilder disease, or myelinoclastic diffuse sclerosis, is a rare progressive CNS demyelinating disorder of childhood (onset 5-14 years), a multiple sclerosis variant with fewer than 20 reported sporadic cases, predominantly male, often mimicking brain tumor or abscess.

Schilling test

Schilling test, a discontinued medical test for vitamin B12 absorption using oral radiolabeled cobalamin and 24-hour urine collection with a 1 mg flushing dose; introduced 1953, obsolete since the 2000s.

Schirmer test

The Schirmer test is an ophthalmology test that measures tear production by placing a filter-paper strip in the lower eyelid and reading the wetted length after five minutes.

Oct 20, 2026

Schisis association

Schisis association (ORPHA:63862) is a rare non-syndromic pattern of congenital anomalies: two or more of neural tube defects, cleft lip/palate, omphalocele, and congenital diaphragmatic hernia, co-occurring above chance rates.

Schistocyte

Schistocyte: a fragmented red blood cell formed by mechanical damage in circulation, also called schizocyte or helmet cell. Key marker of thrombotic microangiopathy; ICSH threshold above 1% of RBCs on smear.

Schistosomiasis due to Schistosoma haematobium

Schistosomiasis due to Schistosoma haematobium, also called urogenital schistosomiasis, is a chronic parasitic disease common in Africa and the Middle East whose classic sign is blood in the urine.

Schistosomiasis due to Schistosoma japonicum

Schistosomiasis japonica (Asiatic schistosomiasis, ICD-11 1F86.2), disease caused by the zoonotic blood fluke Schistosoma japonicum, endemic in China, the Philippines, and Sulawesi, transmitted by Oncomelania snails, treated with praziquantel 60 mg/kg/day.

Schistosomiasis due to Schistosoma mansoni

Schistosomiasis due to Schistosoma mansoni (intestinal/bilharzia) is a chronic blood-fluke infection of mesenteric veins transmitted via freshwater snails, diagnosed by Kato-Katz or CCA urine tests, treated with praziquantel 40 mg/kg, affecting ~253.7 million people needing treatment in 2024.

Schizencephaly

Schizencephaly is a rare congenital brain malformation with gray matter-lined clefts running from ventricle to cortex, classified as closed-lip or open-lip, causing epilepsy, motor deficits, and variable intellectual disability; prevalence about 1.48 per 100,000 births.

Schizoaffective disorder

Schizoaffective disorder, coined by Kasanin in 1933, is a psychiatric diagnosis combining psychotic symptoms with major mood episodes; DSM-5 criteria, prevalence, reliability, course, and the debate over its distinctness from schizophrenia and bipolar disorder.

Schizoid personality disorder

Schizoid personality disorder (SzPD, ICD-10 F60.1) is a Cluster A personality disorder marked by pervasive social detachment and restricted emotional expression, distinguished from avoidant PD by lack of rejection fear, mapped to ICD-11 Detachment.