Diseases and injuries

President's Emergency Plan for AIDS Relief

The President's Emergency Plan for AIDS Relief (PEPFAR) is the United States government's global HIV/AIDS program, launched by President George W. Bush in 2003 and credited with saving 25 million lives.

Pressure ulcer

Pressure ulceration (bedsore, pressure injury, decubitus ulcer; ICD-11 EH90) is localized skin and tissue death from prolonged pressure and shear over bony prominences, staged 1-4 plus deep tissue injury by the NPIAP system.

Pressure-induced localized lipoatrophy

Pressure-induced localized lipoatrophy, also called lipoatrophia semicircularis or semicircular lipoatrophy, is a rare acquired localized lipodystrophy causing band-like thigh depressions from repeated pressure, first described in 1974, mainly in female office workers, and reversible when pressure stops.

Presyncope

Presyncope, or near syncope, is feeling about to faint without losing consciousness, caused by reduced cerebral blood flow; causes include vasovagal, orthostatic, and cardiac conditions, with up to 25% serious outcomes in ED patients.

Preterm birth

Preterm birth, also called premature birth, is birth before 37 completed weeks of gestation; 13.4 million cases in 2020, leading cause of death in children under 5, with categories extremely, very, and moderate to late preterm.

Preterm newborn

Preterm newborn: a baby born alive before 37 completed weeks (259 days) of gestation; ICD-11 code KA21.4. 13.4 million preterm births in 2020; leading cause of under-5 death, with survival strongly tied to income setting.

Preterm premature rupture of membranes

Preterm premature rupture of membranes (PPROM, P-PROM): rupture of the amniotic sac before labor and before 37 weeks; up to 3% of pregnancies, 30-40% of preterm births; managed with erythromycin, corticosteroids, and expectant management to 37 weeks.

Pretibial myxoedema

Pretibial myxoedema (thyroid dermopathy, localized myxoedema) is a rare Graves' disease skin manifestation with hyaluronic acid buildup on the shins, treated first with corticosteroids, emerging teprotumumab.

PREVAIL trial

PREVAIL (NCT01212991, MDV3100-03): phase 3 trial of enzalutamide 160 mg vs placebo in 1,717 chemotherapy-naive men with metastatic castration-resistant prostate cancer; improved rPFS (HR 0.32) and overall survival (HR 0.71 interim, 0.83 at 5 years).

Preventive cardiology

Preventive cardiology is the cardiology subspecialty that assesses a person's risk of atherosclerotic cardiovascular disease and reduces it through risk-factor management, drug therapy, and lifestyle intervention.

Priapism

Priapism is a persistent penile erection unrelated to sexual stimulation, lasting over four hours. Subtypes are ischemic (over 95% of cases, an emergency), non-ischemic, and stuttering; treated by aspiration plus phenylephrine, shunts, or embolization.

Primary acquired pure red cell aplasia

Primary acquired pure red cell aplasia (primary acquired PRCA, primary idiopathic PRCA) is a rare autoimmune bone marrow failure causing isolated loss of red cell production; cyclosporine A outperforms corticosteroids, with relapse common after stopping maintenance.

Primary aldosteronism

Primary aldosteronism (Conn syndrome): autonomous adrenal aldosterone excess causing secondary hypertension, 5-10% of hypertensives, 20% of resistant cases; screened by aldosterone-to-renin ratio, treated with adrenalectomy or mineralocorticoid receptor antagonists.

Primary amenorrhoea

Primary amenorrhoea (primary amenorrhea) is the lifelong absence of menstruation, evaluated by age 15 or 3 years after breast development. Causes span ovarian, outflow tract, hypothalamic, and pituitary disorders; workup starts with pregnancy test and hormone panel.

Primary anal syphilis

Primary anal syphilis (ICD-11 1A61.1, anal syphilitic chancre) is early Treponema pallidum infection forming a chancre in the anal canal after anoreceptive contact; often atypical, misdiagnosed, treated with benzathine penicillin G.

Primary anetoderma

Primary anetoderma, also called primary macular atrophy, is a rare skin disorder in which loss of elastic tissue causes patches of slack, sagging skin with no identifiable cause.

Primary angiitis of the central nervous system

Primary angiitis of the central nervous system (PACNS) is a rare inflammatory disease in which vasculitis is confined to the arteries of the brain and spinal cord.

Primary angle closure glaucoma

Primary angle closure glaucoma (PACG), also called primary angle-closure glaucoma, is glaucoma with iris-trabecular meshwork angle obstruction plus optic nerve damage; pupillary block drives most cases, treated by laser iridotomy or lens extraction, affecting about 17 million people, mostly in Asia.

Primary angle-closure

Primary angle-closure disease (PACD), also called primary angle closure glaucoma spectrum, is iris obstruction of the trabecular outflow pathway, staged as PACS, PAC, and PACG, mainly caused by pupillary block and treated with laser peripheral iridotomy or lens extraction.

Primary antiphospholipid syndrome

Primary antiphospholipid syndrome (PAPS) is antiphospholipid syndrome occurring without another autoimmune disease, unlike secondary APS linked to SLE. It features thrombosis, pregnancy morbidity, and persistent antiphospholipid antibodies, classified by the 2023 ACR/EULAR criteria.

Primary basilar invagination

Primary basilar invagination (primary basilar impression, Bull-Nixon syndrome) is a rare congenital upward translocation of the upper cervical spine and clivus into the foramen magnum, autosomal dominant, often with Chiari I malformation, diagnosed by Chamberlain, McGregor, and McRae line criteria and treated surgically.

Primary biliary cholangitis

Primary biliary cholangitis (formerly primary biliary cirrhosis) is a chronic autoimmune liver disease destroying small bile ducts, affecting middle-aged women, diagnosed by ALP elevation and AMA, treated first with ursodeoxycholic acid.

Primary biliary cholangitis/primary sclerosing cholangitis and autoimmune hepatitis overlap syndrome

Primary biliary cholangitis/primary sclerosing cholangitis and autoimmune hepatitis overlap syndrome is an uncommon liver disorder in which autoimmune hepatitis occurs alongside primary biliary cholangitis or primary sclerosing cholangitis.

Primary bone lymphoma

Primary bone lymphoma is a rare lymphoma arising in bone with no disease elsewhere, usually diffuse large B-cell type, causing progressively worsening local bone pain.

Primary choroidal lymphoma

Primary choroidal lymphoma (PCL), a rare low-grade extranodal marginal zone B-cell lymphoma of the choroid, formerly called reactive lymphoid hyperplasia; indolent, no CNS spread, good prognosis, treated with radiotherapy or rituximab.

Primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD, Kartagener syndrome when with situs inversus) is a rare autosomal recessive ciliopathy of motile cilia causing chronic sinopulmonary disease, laterality defects, and infertility, diagnosed by nNO, TEM, and genetics.

Primary congenital glaucoma

Primary congenital glaucoma (PCG), also called trabeculodysgenesis or primary infantile glaucoma, is a rare bilateral childhood glaucoma from trabecular meshwork malformation; treated surgically (goniotomy, trabeculotomy), linked to CYP1B1, LTBP2, TEK genes.

Primary cutaneous actinomycosis

Primary cutaneous actinomycosis (ICD-11 1C10.3) is a rare primary skin infection by Actinomyces, chiefly A. israelii, after trauma; diagnosed by excluding deeper foci and sulfur granules, treated with penicillin for 6-12 months.

Primary cutaneous aggressive epidermotropic CD8+ T-cell lymphoma

Primary cutaneous aggressive epidermotropic CD8+ T-cell lymphoma, or Berti lymphoma, is a rare, highly aggressive skin T-cell lymphoma under 1% of CTCL, marked by rapidly ulcerating lesions, spread to lung and CNS, and about 18% five-year survival.