USMLE Step 2 (Fach) / Infectious disease (Lektion)
In dieser Lektion befinden sich 103 Karteikarten
Step 2 CK
Diese Lektion wurde von estoffel erstellt.
- Pneumonia Pathogens:- Typical pneumonia: Streptococcus pneumoniae, Haemophilus influenzae- Atypical pneumonia: Mycoplasma pneumoniae (most common in the ambulatory setting), Chlamydophila pneumoniae, Legionella ...
- Tuberculosis Epidemiology:- Countries with the highest incidence: India, Indonesia, China, Nigeria, Pakistan, and South Africa Risk factors:- For active disease (i.e., reactivation): Immunosuppression (HIV/AIDS), ...
- Acute pharyngitis Etiology:- Bacterial: Group A streptococci (GAS), Neisseria gonorrhoeae, Corynebacterium diphtheriae, M pneumoniae.- Viral: Rhinovirus, coronavirus, adenovirus, HSV, EBV, CMV, influenza virus, coxsackievirus, ...
- Cytomegalovirus - Seroprevalence: 70% of adults in the United States- Transmission: Congenital, sexual intercourse, transfusions, transplants, saliva, urine Clinical presentation:- Heterophile-negative mononucleosis- CMV ...
- Mycobacterium avium complex Most frequent opportunistic bacterial infection in AIDS patients.- Occurs usually only if CD4 count < 50/μL. Clinical presentation:- Night sweats, fever, weight loss- Lymphadenopathy- Abdominal pains, ...
- Brain abscess Pathogens:- Viridans streptococci (∼50% of cases), often secondary to sinusitis- Staphylococcus aureus (10-15% of cases)- Coagulase-negative staphylococci (∼10% of cases)- Obligate anaerobes (eg, ...
- Meningitis Risk factors:- Otitis media, sinusitis- CSF leak after head trauma or neurosurgery- Immunocompromise (e.g., AIDS, asplenia, alcoholism, chronic illness, sickle cell anemia)- Maternal group B Streptococcus ...
- Encephalitis Etiology:- HSV and arboviruses (most common)- Rare: CMV, toxoplasmosis, West Nile virus, VZV, Borrelia, Rickettsia, Legionella, enterovirus, Mycoplasma, and cerebral malaria. - Children and the elderly ...
- Fever of unknown origin A temperature of >38.3°C (> 100.9°F) of at least 3 weeks’ duration that remains undiagnosed following 3 outpatient visits or 3 days of hospitalization. Differential:- Infectious: TB, endocarditis ...
- Lung abscess A localized collection of pus and necrotic tissue within lung parenchyma caused by microbial infection. Risk factors:- Aspiration due to reduced level of consciousness, dysphagia- Bronchial obstruction: ...
- Influenza Epidemiology:- Seasonal pattern: Fall and winter Clinical features:- Incubation period: a few hours to several days- Sudden onset of high fever, chills, headache, muscle/joint aches, fatigue, and malaise- ...
- Urinary tract infection Pathogens:- Escherichia coli: in ∼ 80% of UTIs- Proteus mirabilis: urease-producing → causes alkaline urine with an ammonia smell- Klebsiella pneumoniae- Enterobacter species- Others: Staphylococcus ...
- Pyelonephritis Pathogens:- Escherichia coli (∼ 75-90% of cases) - Pseudomonas aeruginosa- Klebsiella pneumoniae- Proteus mirabilis- Gram-positive bacteria (e.g., Enterococcus faecalis, Staphylococcus aureus) Risk ...
- Human immunodeficiency virus (HIV) Acute HIV infection:- Also referred to as acute retroviral syndrome (ARS) or described as a mononucleosis-like syndrome. - Fever, fatigue, myalgia and arthralgia, headache- Generalized nontender lymphadenopathy- ...
- Syphilis Epidemiology:- Sex: M > F (10:1)- Peak incidence: 20-29 years Etiology:- Pathogen: Treponema pallidum- Transmissibility: 30% in active disease (stadium I/II)! Clinical features:1. Primary syphilis- Primary ...
- Chancroid Chancroid (also known as soft chancre) is a highly contagious STI caused by Haemophilus ducreyi. Clinical features:- Very painful genital ulcers- The primary lesions are erythematous papules that become ...
- Lymphogranuloma venerum A sexually transmitted disease caused by C. trachomatis. Clinical features:- Painless ulcer at the site of inoculation that may go unnoticed. - A few weeks later, tender inguinal lymphadenopathy (usually ...
- Cellulitis A deeper skin infection involving dermis and subcutaneous tissue. Pathogen:- Staphylococcus aureus → causes purulent cellulitis- Streptococcus pyogenes (group A Streptococcus) → causes nonpurulent ...
- Erysipela Superficial skin infection involving the upper dermis, with lymphangitis and lymphadenitis. Pathogen: group A Streptococcus (Streptococcus pyogenes)- The most common portal of entry for the pathogen is ...
- Necrotizing fasciitis Rapidly progressive infection resulting in extensive necrosis of deep tissue (subcutaneous tissue, fascia, and muscle) and systemic infection that can develop into a life-threatening condition within ...
- Osteomyelitis Pathogens:- Staphylococcus aureus: Children and adults- Staphylococcus epidermidis: Diabetic patients with foot ulcers and pressure ulcers; Patients with prosthetics- Streptococci: Diabetic patients ...
- Fever of unknown origin Definition:- Fever >38.3°C (101°F)- Continuing “on several occasions” for at least 3 weeks- No diagnosis over this time period despite 1 week of inpatient workup / 3 outpatient visits Etiology:- ...
- Neutropenic fever Neutropenic patient with fever and a neutrophil count ≤ 500/μL (severe risk of bacterial infection). Etiology:- Often chemotherapy-induced. - Bacterial infections, aspergillosis, candidiasis, herpes ...
- Sepsis - Definition Sepsis: acute and life-threatening organ dysfunction due to abnormal host response to infection.- Organ dysfunction = an acute change in total SOFA score ≥ 2 points- Infection = may be confirmed (via ...
- Lyme disease PathogenIn the US: - Borrelia burgdorferi, an anaerobic, facultative intracellular spirochete bacteria Vector: mainly Ixodes scapularis (deer or black-legged tick) in the northeastern and upper midwestern ...
- Ehrlichosis Pathogen: Ehrlichia chaffeensis, Ehrlichia ewingii (intracellular, gram-negative bacteria) Epidemiology: southeastern and south central US, mid-Atlantic States Reservoir: white tail deer Route of transmission: ...
- Giardiasis Epidemiology:- Giardia lamblia is widespread throughout the world and affects ∼ 200 million people per year worldwide.- In the US, Giardiasis is the most common intestinal disease caused by parasites. ...
- Legionella pneumonia Epidemiology:- Contaminated water: Hospital, travel (cruise, hotel)- High-risk patients: Elderly, patients with chronic diseases, immunocompromised individuals, smokers Clinical features:- Fever > 38.8 ...
- Cat scratch disease Etiology:- Bartonella henselae, fastidious gram-negative bacilli- Can be transmitted by cat scratch/bite Clinical features:- General: malaise, loss of appetite, fever- Papule at scratch/bite site ...
- Vaccines for adults with HIV HAV: - Chronic liver disease (including HBV & HCV)- Men who have sex with men- IV drug users HBV: All patients without documented immunity to HBV HPV: All patients age 11-26 Influenza: Annually for all ...
- Vibrio vulnificus Epidemiology:- Gram-negative, free-living in marine environments- Ingestion (oysters) or wound infection- ↑ Risk in those with liver disease (cirrhosis, hepatitis) Clinical features:- Rapidly progressive ...
- Disseminated histoplasmosis Epidemiology:- Midwest & central United States (Ohio & Mississippi River Valleys)- Soil contaminated by bird or bat droppings- ↑ Dose exposure or immunocompromised (eg, AIDS) Clinical features:- Systemic: ...
- Hookworm infections Pathogen: - Human hookworms: Ancylostoma duodenale, Necator americanus- Zoonotic hookworms: Dog (Ancylostoma caninum) or cat (Ancylostoma braziliense) Mode of transmission: Percutaneous penetration of ...
- Tetanus prophylaxis ≥ 3 tetanoid toxoid doses:- No TIG- Clean or minor wound: Tetanus vaccine if last dose ≥ 10 years ago- Dirty or severe wound: Tetanus vaccine if last dose ≥ 5 years ago Unimmunized, uncertain, or ...
- Disseminated gonococcal infection Clinical features:- Purulent monoarthritis &/OR - Triad of tenosynovitis, dermatitis (erythematous papules & pustules), asymmetric migratory polyarthralgias Diagnosis:- Blood cultures (may be negative)- ...
- Actinomycosis Pathogen: Anaerobic, gram ⊕, form branching filaments. Not acid fast (unlike Nocardia). Risk factors:- Dental infections & trauma (extraction)- Immunosuppression, diabetes mellitus, malnutrition Cervicofacial ...
- Staphylococcal toxic shock syndrome Risks:- Tampon use- Nasal packing- Surgical/postpartum would infection Pathogenesis: Staphylococcus aureus exotoxin release acting as superantigens Clinical features:- Fever > 38.9 °C- Hypotension- ...
- Mucormycosis Etiology: Mucorales, most commonly Rhizopus Risk factors:- Diabetes mellitus (ketoacidosis)- Immunosuppression: Hematologic malignancy, solid organ or stem cell transplant- Iron overload Clinical features:- ...
- Echinococcosis Pathogens:- Echinococcus granulosus: causes cystic echinococcosis- Echinococcus multilocularis: causes alveolar echinococcosis Transmission:- From the fur of definitive hosts (eg, dogs or cats)- Contaminated ...
- Chikungunya fever Epidemiology:- Tropical/subtropical parts of Central/South America, Africa & Asia- Vector: Aedes mosquito (also transmits dengue & Zika) Clinical features:- Incubation period: 3-7 days- High fevers & ...
- Necrotizing (malignant) otitis externa Risk factors:- Elderly (age > 60)- Diabetes mellitus- Aural irrigation (cerumen removal) Microbiology: Pseudomonas Clinical features:- Severe, unremitting ear pain (worse at night & with chewing)- Deficits ...
- Pertussis Etiology:- Pathogen: Bordetella pertussis is a gram‑negative, obligate aerobic coccobacillus- Transmission: airborne droplet (through coughing); direct contact with oral or nasal secretions Clinical ...
- Causes of esophagitis in HIV Candida albicans:- White plaques- Oral thrush Herpes simplex virus:- Herpetic vesicles & round/ovoid ulcers- Concurrent perioral/oral HSV- Superficial Cytomegalovirus:- Deep, linear ulcers- Distal esophagus ...
- Ecthyma gangrenosum An ulcerative lesion extending into the dermis that develops in the setting of bacteremia. Pathogen: Pseudomonas aeruginosa Pathophysiology:- Classically develops in patients with P aeruginosa bacteremia ...
- Bacterial endocarditis prophylaxis High-risk cardiac conditions:- Prosthetic heart valve- Previous infective endocarditis- Structural valve abnormality in transplanted heart- Certain congenital heart disease Indicated procedures & appropriate ...
- Acute rheumatic fever Epidemiology:- Peak incidence: age 5-15- Twice as common in girls Clinical features:Major:- Joints (migratory arthritis)- Carditis- Nodules (subcutaneous)- Erythema marginatum- Syndeham choreaMinor:- ...
- Preseptal vs orbital cellulitis Preseptal cellulitis- Eyelid erythema & swelling- Chemosis- Treatment: Oral antibiotics Orbital cellulitis:- Symptoms of preseptal cellulitis + Pain with EOM, proptosis &/or ophthalmoplegia with diplopia- ...
- Trichinellosis Epidemiology & life cycle:- Ingestion of undercooked meat (usually pork)- More endemic in Mexico, China, Thailand, parts of central Europe & Argentina- Gastric acid releases larvae that invade small intestine ...
- Syphilis treatment Primary: Penicillin G (IM) x 1 dose- Alternate: Doxycycline x 14 days Secondary: Penicillin G (IM) x 1 dose- Alternate: Doxycycline x 14 days Latent (asymptomatic): Penicillin G (IM) x 3 doses- Alternate: ...
- Bacillary angiomatosis Epidemiology:- Bartonella henselae/quintana- Cat exposure or homelessness (lice)- Severe immunocompromise: Advanced HIV (CD4 < 100/mm3) Manifestations:- Vascular cutaneous lesions: Papular, nodular, peduncular; ...