Human health and medicine

Subcutaneous fat necrosis of the newborn

Subcutaneous fat necrosis of the newborn (SCFN, neonatal subcutaneous fat necrosis) is a rare self-limited panniculitis of term infants causing firm purple nodules, linked to asphyxia and therapeutic hypothermia, and complicated by hypercalcemia.

Subcutaneous immunotherapy

Subcutaneous immunotherapy (SCIT) is an allergy treatment injecting increasing allergen doses under the skin to induce immune tolerance, used for rhinitis, asthma, and venom allergy.

Subcutaneous implantable cardioverter-defibrillator

Subcutaneous implantable cardioverter-defibrillator (S-ICD), EMBLEM S-ICD: a defibrillator with a single lead entirely under the skin, no transvenous lead. PRAETORIAN showed noninferiority to transvenous ICDs; PRAETORIAN-XL showed 42% fewer major complications at 8 years; no antitachycardia pacing.

Subcutaneous infusion

Subcutaneous infusion, also called hypodermoclysis, is a method of delivering fluids or medications into subcutaneous tissue, used mainly for mild to moderate dehydration in older adults.

Subcutaneous injection

A subcutaneous injection delivers medication into fatty tissue beneath the skin, a less invasive route than intravenous dosing that can be performed at home and provides slower, sustained absorption.

Subcutaneous lipomatosis

Subcutaneous lipomatosis (ICD-11 EF02.1), also called benign symmetrical lipomatosis or Madelung disease, is diffuse infiltration of subcutaneous fat by non-encapsulated adipose tissue, including Dercum disease and congenital infiltrating forms.

Subcutaneous mastectomy

Subcutaneous mastectomy, also known as nipple-sparing mastectomy, is a surgical procedure that removes nearly all breast tissue while preserving the skin envelope and nipple-areola complex.

Subcutaneous mycoses

Subcutaneous mycoses (implantation mycoses, ICD-11 EA60.0) are chronic fungal infections of skin and subcutaneous tissue from traumatic inoculation, chiefly chromoblastomycosis, mycetoma, and sporotrichosis, mostly tropical and rarely systemic.

Subcutaneous panniculitis-like T-cell lymphoma

Subcutaneous panniculitis-like T-cell lymphoma is a rare cutaneous T-cell lymphoma that invades subcutaneous fat, forming nodules that resemble panniculitis and usually following an indolent course.

Subcutaneous tissue

Subcutaneous tissue (tela subcutanea, hypodermis, superficial fascia) is the loose connective and fatty layer beneath the dermis; it insulates, cushions, stores energy, and is the target of subcutaneous injections.

Subdural hematoma

Subdural hematoma: bleeding between the dura mater and brain surface, usually from torn bridging veins after head injury. Acute forms are surgical emergencies; chronic forms affect older adults, and middle meningeal artery embolization now reduces recurrence after drainage.

Subdural hygroma

Subdural hygroma (SDHy, SDG): a subdural collection of pure CSF from traumatic arachnoid tearing or effusion in intracranial hypotension, dehydration, or atrophy; coined by Dandy 1934; may convert to chronic subdural hematoma.

Subependymal giant cell astrocytoma

Subependymal giant cell astrocytoma (SEGA), a benign slow-growing grade 1 brain tumor of the ventricle walls, occurring almost exclusively in tuberous sclerosis complex; treated by surgery or everolimus.

Subependymoma

Subependymoma: rare WHO grade 1 ependymal tumor of the brain or spinal cord, mainly in adults around age 50, arising in the fourth and lateral ventricles, with excellent prognosis after surgical resection.

Subepithelial connective tissue graft

A subepithelial connective tissue graft is a periodontal surgery technique, reported by Burton and Laureen Langer in 1985, using palatal connective tissue to cover exposed tooth roots and thicken gum tissue around teeth and implants.

Subepithelial mucinous corneal dystrophy

Subepithelial mucinous corneal dystrophy (SMCD) is a rare autosomal dominant corneal disorder, first described in 1993, causing painful recurrent erosions in childhood and progressive corneal clouding in adulthood.

Suberosis

Suberosis (corkworker's lung, ICD-10 J67.3, ICD-11 CA70.3) is a hypersensitivity pneumonitis of cork workers caused by moldy cork dust, mainly Penicillium glabrum or P. frequentans, first identified in 1955.

Subgingival Curettage

Subgingival curettage, also called gingival curettage or periodontal epithelial debridement, is removal of the epithelial lining of periodontal pockets with a curette; abandoned after trials showed no benefit over scaling and root planing.

Subgroup analysis

Subgroup analysis is a statistical method that estimates treatment effects separately within patient subsets defined by baseline characteristics, testing whether the effect differs across groups.

Subjective refraction

Subjective refraction is the assessment of refractive error by presenting lenses and using patient responses to find the best correction, the gold standard for spectacle prescription.

Sublingual administration

Sublingual administration places a drug under the tongue for absorption through oral mucosa into systemic circulation, bypassing hepatic first-pass metabolism; used for nitroglycerin, buprenorphine, fentanyl, and nicotine.

Sublingual immunotherapy

Sublingual immunotherapy (SLIT) is an allergy treatment in which allergen tablets or drops held under the tongue desensitize patients with allergic rhinitis or asthma, an alternative to injected immunotherapy.

Sublingual varices

Sublingual varices, also called caviar tongue or lingual varicosities, are benign dilated tortuous veins under the tongue, affecting roughly 23–35% of adults, increasing with age, and associated with hypertension, smoking, and cardiovascular disease.

Sublobar resection

Sublobar resection is an operation for early-stage non-small-cell lung cancer that removes part of a lung lobe rather than the whole lobe, preserving more lung function.

Subluxation

Subluxation: in medicine, a partial joint dislocation; in chiropractic, a putative spinal lesion central to the profession since DD Palmer's 1895 founding, whose detection and clinical significance remain scientifically contested.

Subluxation of tooth

Subluxation of tooth (ICD-11 NA0D.11): a traumatic dental injury to periodontal tissues causing abnormal tooth loosening without displacement, with gingival sulcus bleeding; managed conservatively with soft diet and radiographs.

Submandibular gland

Submandibular gland: paired major salivary gland below the mandible, second largest after the parotid; drains via Wharton's duct, makes ~70% of resting saliva, and accounts for over 80% of salivary stones.

Submissiveness

Submissiveness (ICD-11 MB28.H): a behavioral tendency to adapt one's actions to others' real or perceived wishes against one's own interests; studied as a trait linked to social anxiety, depression, and distress intolerance.

Submucosal cleft palate

Submucosal cleft palate (SMCP, ORPHA:155878) is a congenital cleft palate variant with midline soft palate muscle diastasis under intact mucosa, diagnosed by Calnan's triad of bifid uvula, zona pellucida, and hard palate notch; occult forms lack the triad.