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R5 - Internal Medicine > Infectious Disease > Flashcards

Infectious Disease Flashcards

1
Q

HIV

A
  • women infected younger than men, 76% men (exposed via MSM, IVDU, heterosexual contact, MSM + IVDU)
  • transmission: blood-blood
  • RF: sex w/ infected person, IV exposure to infected blood by transfusion or needle sharing, perinatal exposure
  • sxs: asx (mean 10y); primary HIV infxn → fever, night sweats, wt loss, skin lesions, pharyngitis, swollen lymph nodes → lasts days-weeks)
  • signs: hair leukoplakia, dissem kaposi sarcoma, cutaneous bacillary angiomatosis, gen LAD
  • dx: HIV ELISA, western blot (confirmatory), HIV rapid Ab test, CBC (anem, neutropen, thrombocytopen), absolute CD4 (monitor q3-6mos), CD4 %, viral load, CXR, blood cx if fever, crytococcal Ag, sinus CT or XR
  • tx: start tx regardless of CD4 and perform resistance testing prior to ART initiation; primary goal is complete suppression of replication; combo tx w/ at least 3 meds
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2
Q

AIDS

A
  • coccidioidomycosis, enceph, histoplasmosis, isosporiasis with D >1mo, kaposi, lymphoma of brain, non-hodgkin lymphoma of B cell, MAC, extrapulm TB, salmonella septicemia, HIV wasting syndrome, pulm TB, recurrent PNA, invasive cervical CA
  • dx: HIV serology +, CD4 count <200cells or <14%
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3
Q

lyme disease

A
  • northeastern (main-maryland), midwest, west coast; incubation = 3-32d
  • transmission: ticks, mice, deer; caused by Borrelia burgdorferi
    • stage 1: erythema chronicum migrans (hallmark) → large, painless, well-demarcated target shaped lesion on trunk, thigh, groin, axilla
    • stage 2: disseminated, flu like sxs (HA, stiff neck, fever/chills, fatigue, malaise, myalgias); after a few weeks → meningitis, encephalitis, cranial neruitis, peripheral radiculoneruopathy, bell palsy; within wks to mos → AV block, pericarditis, carditis
    • stage 3: late, persistent; arthritis large jnts, chronic CNS dz, mild enceph, transverse myelitis, axonal polyneuropathy, acrodermatitis chronica atrophicans (reddish-purple plaques and nodules on extensor surfaces of legs)
  • clinical dx: ELISA in 1st mo, western blot to confirm
  • tx: early disease, localized → 10d abx; if beyond skin, PO doxy x21d (amox and ceguroxime are alternatives)
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4
Q

mononucleosis (what do you not give)

A
  • caused by epstein-barr virus (rarely CMV), adolescents, college students, or military recruit
  • transmisison: saliva, 90% adults infected previously are carriers, lifelong immunity w/ 1 infxn
  • sxs: fever, LAD, pharyngitis → fever resolves in 2 wks, sore throat, malaise, myalgias, weakness
  • signs: LAD, posterior cervical, tonsillar, enlarged, painful, tender; pharyngeal erythema and/or exudate, splenomegaly, maculopapular rash, hepatomeg, palatal petechiae and periorbital edema
  • dx: monospot, WBC count with diff, transaminitis, EBV specific Ab, peripheral smear shows lymphocytic leukocytoisis with large, atypical lymphocytes
  • tx: supportive, short course steroids, avoid sports 3-4wks (SPLENIC RUPTURE)
  • complicaitons: hep, meningoencephalitis, Guillain Barre, splenic rupture, thrombocytopenia, URTI
  • DONT GIVE AMOX or AMP → can cause maculopap rash
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5
Q

influenza

A
  • orthomyxovirus
  • transmission: resp droplets, winter months
  • sxs: rapid onset of fever, chills, malaise, myalgia (legs or lumbosacral area), fever, HA (generalized or frontal), nonproductive cough (may last more than 1 wk), ocular signs/sxs (pain w/ motion of eyes, photophob, bruning of eyes), sore throat, +/-N
  • signs: cervical LAD, rhonchi, wheezes, scattered rales
  • dx: RT-PCR = most sensitive and specific (can differentiate subtypes and detect avian flu
  • tx: supportive care (tylenol or NSAIDs . for HA, myalgias, fever; no cough suppressants, neruaminidase inhib: zanamivir or oseltamivir for flu type A and B → reduces sxs by 1-1.5d if started w/in 2 days of onset
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6
Q

Chlamydia etiology and sxs

A
  • Most common bacterial STD
  • RF: lack of condom use, lower socioeconomic status, living in an urban area, having multiple sex partners
    • most common in F 15-19, then 20-24
    • independent risk factor for cervical cancer
  • Sxs:
    • men: dysuria, purulent urethral discharge, itching, scrotal pain and swelling, fever
    • women: puruelnt urethral discharge, intermenstrual or post-coital bleeding, dysuria
      • mucopurulent discharge from cervical os, friable cervix
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7
Q

chlamydia diagnostics and tx

A
  • Tx: NAAT, wet mount (leukorrhea >10 WBC), culture, enzyme immunoassay, PCR
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8
Q

Gonorrhea etiology and sxs

A
  • transmitted sexually or neonatally
  • 30% coinfected with chlamydia
  • Sxs: asymptomatic in women, symptomatic in men
    • Cervicitis or urethritis (purulent discharge, dysuria, intermenstrual bleeding)
    • Disseminated: fever, arthralgias, tenosynovitis, septic arthritis, endocarditis, meningitis, skin rash (distal extremities)
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9
Q

Gonorrhea dx and tx

A
  • dx: NAAT, gram stain (leukocytes, gram neg intracell. diplococci), cultures (men from urethra, women from endocervix)
  • tx: tx empirically because cultures take 1-2d
    • Ceftriaxone x1, add Azithromycin or doxy to cover chlamydia
    • if disseminated, hospitalize and IV or IM ceftriaxone
  • Complications of dz: PID, infertility, epididymitis, prostatitis, salpingitis, tubo-ovarian abscess, Fitz-Hugh-Curtis syndrome
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10
Q

Herpes simplex virus (herpes labialis), HSV-1

A
  • transmission: kissing, resides in trigeminal ganglion
  • signs and sxs: fever, malaise, vesiculopustular oral lesions in groups
    • herpes labialis (cold sores): most common on lips, painful, heal in 2-6 wks
    • bell palsy
    • herpetic whitlow
  • dx: clinical dx with lesions dewdrop on a rose petal
    • tzanck smear - multinucleated giant cells
    • culture of HSV
    • ELISA
    • PCR
  • tx: acyclovir
  • complications: herpes encephalitis, HSV keratitis
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11
Q

Genital herpes, HSV-2

A
  • resides in sacral ganglion
  • prior HSV-1 infxn confers partial immunty to HSV2
  • signs and sxs: severe, prolonged sxs
    • fever, HA, malaise
    • painful vesicles on genitals (itching, dysuria, multiple, bilateral)
    • tender inguinal lymph nodes
  • dx: HSV1 and HSV2 Ab negative
    • PCR, culture if active lesion present
  • tx: acyclovir, sitz baths, topical xylocaine
  • complications: aseptic meningitis, keratitis, blepharitis, keratoconjunctivitis
  • C section recommended for pregnant women with active infxn
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12
Q

candidiasis

A
  • 2nd MCC vaginitis
  • RF: high dose OCP, diaphragm use, DM, abx, pregnant, immune suppression, tight clothes
  • signs, sxs: vulvar or vag itching, burning, external dysuria, dyspareunia, odorless thick cottage cheese curd-like d/c
    • erythema of vulva, excoriations from scratching
  • dx: wet mount - budding yeast
    • gram stain - pseudohyphae
    • vaginal culture (+) for yeast
    • pH <4.7 (acidic)
  • tx: fluconazole 150 PO once
    • tx uncircumcised partners
    • short-course topical azole
    • recurrent: weekly topical /PO
    • resistant: boric acid TID x7d
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13
Q

primary, secondary, latent, and tertiary syphilis

A
  • TREPONEMA PALLIDUM
  • Primary:
    • chancre - painless, clean base, 3-4wk after exposure, heals in 14wk w/o light tx, HIGHLY INFXS
    • inguinal lymphadenopathy
  • Secondary:
    • flu-like (HA, fever, sore throat, malaise)
    • 4-8 wks after chancre heals, maculopapular rash
    • aseptic meningitis
    • 1/3 develop latent syphilis
  • Latent:
      • serological test in absence of clinical sxs
    • 2/3 remain asymptomatic
    • “early latent” = if serology + for <1 y, may relapse to secondary
    • “late latent” = if serology + for >1y, patients are contagious
  • Tertiary:
    • years after primary infxn
    • neurosyphilis, CV syphilis, gummas
      • neurosyph: dementia, personality changes, tabes dorsalis (post column degen, loss of corrdination of mvmt)
    • rare d/t tx with PCN
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14
Q

Syphilis dx and tx

A
  • Dark field microscopy (GOLD STANDARD)
  • Serologic tests (MC)
    • Non-treponemal tests: RPR, VDRL
    • Treponemal tests: FTA-ABS, MHA-TP
      • if FTA-ABS +, check for CSF-FTA-ABS
  • test all pts for HIV
  • Tx: PCN G (one dse IM)
    • doxy and tetra x2wks if PCN allergy
    • latent or tertiary: PCN x3 doses IM (1 wk apart)
    • neurosyph: IV PCN x 10-14d
      • repeat nontreponemal tests q3 mos
    • Jarisch-Herxheimer rxn can occur w/ sudden massive destruction of spirochetes - prevent by administering antipyretics during first 24h of tx
  • Report to public health agency
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15
Q

Crytosporidiosis, Amebiasis, Giardiasis

A
  • Crytposporidiosis: spore-forming protozoa
    • Trans: fecal-oral
    • sxs: watery D
    • dx: stool sample (oocytes)
    • tx: supportive
  • Amebiasis: Entamoeba histolytica (protozoa)
    • trans: fecal-oral, food/H2O, anal-oral
    • sxs: bloody D, tenesmus, abd pain, +/- liver abscess
    • dx: stool sample (trophozoites)
    • tx: Iodoquinol or paromomycin, Flagyl for liver abscess
  • Giardiasis: Giardia lamblia (protozoa)
    • Trans: fecal-oral, food/H2O, anal-oral
    • Incubation: 1-3wk“foul smelling D”
    • sxs: fatty D, D w/ cramps, N, malaise, anorexia, flatulence, bloating
      • hx: daycare, recent camping trip, watery D, chonic infxn w/ wt loss
    • dx: stool sample (cysts or trophozoites)
    • tx: supportive, abx (tinidazole, nitaxonide, Flagyl (metro))
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16
Q

Roundworm, Hookworm, Pinworm

A
  • Roundworm (ascariasis; nematode)
    • trans: fecal-oral
    • sxs: asx, if sx - PP abd pain, V (associated = bowel, panc duct, or CBD obstruction if heavy worm burden)
    • dx: stool sample (eggs or adult worms)
    • tx: albendazole, mebendazole, pyrantel pamoate
  • Hookworm (Necator americanus)
    • trans: larvae enter skin → lungs → cough, swallow → reside in intestine
    • sxs: asx, if sx - cough
    • signs: malabs/wt loss, eosinophilia, anemia
    • dx: stool sample (adult worms)
    • tx: mebendazole or pyrantel pamoate
  • Pinworm (Enterobius vermicularis)
    • trans: fecal-oral (children)
    • sxs: perianal pruritus, worse at night
    • dx: “tape test” on anus (eggs on tape)
    • tx: mebendazole or pyrantel pamoate
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17
Q

tapeworm, schistosomiasis

A
  • tapeworm (taenia saginata, T. solium, Diphyllobothrium latum)
    • trans: raw or undercooked meat
    • sxs: asx, if sx - N, abd pain, wt loss, B12 def
    • dx: tape test or stool sample (eggs)
    • tx: praziquantel, vitamin B12 if def
  • Schistosomiasis (Schistosoma mansoni, S. haematobium, S. japonicum)
    • trans: penetration of skin → lungs → portal vein → venules of mesenteric, bladder, ureters
    • sxs: dermatitis, local erythema, pruritic maculopap rash, fever, myalgias, malaise, abd pain, HSM, HA, cough, +/- bloody D
    • dx: eggs in urine or feces
    • tx: praziquantel
18
Q

Tuberculosis

A
  • can present as acute or latent infxn
  • only active TB is contagious (cough, sneezing), PRIMARY TB IS NOT CONTAGIOUS
  • difficult to dx in HIV, PPD will be neg, atypical CXR findings, sputum likely neg, granuloma may not be present
  • RF: HIV, immigrants, prisoners, health care workers, close contact, alcoholics, DM, steroids, blood malig, IVDU
  • MC: mycobacterium tuberculosis, slow growing
  • Transmission: inhalation of aerosolized droplets
  • sxs: fatigue, weight loss, fever, night sweats, productive cough
  • dx: sputum stain (acid fast bacilli), sputume culture + for M. tuberculosis, PPD, CXR (caseating granuloma formation (pulm opacitis, most often atypical)
  • tx: RIPE tx, dc tx if transaminases >3-5x ULN, can spread to vertebral column
19
Q

Primary, Secondary, and Extrapulmonary TB

A
  • Primary: bacilli inhaled and deposited into lung - ingested by alveolar macrophages
    • surviving orgs multiply and disseminate via lymphatics and blood
    • granulomas form and “wall off” mycobacteria - remains dormant
    • insults on immune syst reactivates (5-10%)
    • Asymptomatic: pleural effusion, can be progressive with pulm and constitutional sxs, usually clinically and radiographically silent
  • Secondary: Host’s immunity weakened (HIV, malignancy, steroids, substance abuse, poor nutrition), gastrectomy, silicosis, DM)
    • most oxygenated parts of lung: apical/posterior segments
    • Symptomatic: fever, night sweats, weight loss, malaise, chronic cough, progressive (dry to purulent, blood streaked)
      • signs: chronically ill appearing, malnourished, posttussive apical rales
  • Extrapulmonary TB: impaired immunity cannot contain bacteria - disseminates (HIV)
    • any organ
    • Miliary TB: hematogenous spread - can be due to reactivation or new infxn, HIV pts, organomegaly, reticulonodular infiltrates, choroidal tubercles in eye
20
Q

TB diagnostics

A
  • high index of suspicion depending on RF and presentation
  • CXR - unilateral apical infiltrates with cavitations, hilar and paratracheal lymph node enlargement, pleural effusions, Ghon complex, Ranke complex
    • HIV may show lower lung zone, diffuse, or miliary infiltrates
  • Sputum studies: definitive dx by sputum culture, obtain 3 morning sputum speciments, takes 4-8wks, PCR can detect specifics
  • PPD (Mantoux test): screening to detect previous TB exposure, not for active TB dx; if + use CXR to r/o active TB
    • if sxatic or abnl CXR, order AFB
    • >15mm if no risk factors; >10 if high risk (homeless, imigrants, health care workers, DM); >5 if very high risk (HIV, organ transplant, contact with active TB)
  • Interferon gamma release assay: measures interferon gamma release in response to MTB antigens, helps exclude false + TST
  • blood cultures
  • NAAT-R
21
Q

signs of healed primary TB:

A
  • Ghon complex: calcified focus with associated lymph node
  • Ranke complex: Ghon complex undergoes fibrosis and calcification
  • CXR: fibrocavitary apical dz, discrete nodules, pneumonic infiltrates usually in apical or posterior segments of upper lobes or in superior segments of lower lobes
22
Q

TB treatment: active TB, Pregnant women, Latent TB, Immunnocompetent, HIV pos

A
  • Active TB: droplet precautions; isolation until sputum neg for AFB
    • 2 months of tx with 4 drug RIPE, then 4 months with INH and Rifampin
    • once isolate determined to be isoniazid sensitive, ethambutold can be DCed; if susceptible to isoniazid and rif, may continue on 2-drug regimens
    • tx >/= 3 mos past neg cxs for MTB
  • Pregnant: DONT TAKE PYRAZINAMIDE: RIE x 2mo, then isoniazid and rif for 7 mo; B6 (pyridoxine) daily to prevent periph neuropathy; breastfeeding NOT contraindicated
  • Latent (+ PPD): 9mo INH AFTER active TB excluded via CXR, sputum, or both; NOT infxous, no active dz
  • Immunocompetent: INH x9mo; adverse effect = drug induced hepatitis
  • HIV pos: 9mo INH OR 2mo rif and pyrazinamide OR rif x 4mo
  • Other: 9 mo tx when miliary, meninegal or bone/jnt dz; surgical drainage and debridement of necrotic bone in skeletal dz; steroid tx to prevent constrictive pericarditis and neuro complications
23
Q

varicella infxn

A
  • chickenpox
  • incubation: 14d
  • sxs: fever, rash on face/scalp, moves to trunk/extremities
  • signs: papules and vesicles, crusts “dew drop on a rose petal”
  • dx: tzanch smear to confirm herpes simplex, varicella, and zoster infxn
  • tx: valacyclovir decreases incidence of varicella PNA
24
Q

pertussis etiology, RF, and sxs

A
  • Bordetella pertussis - G- coccobacilus, highly contagious during catarrhal stage, transmitted via resp droplets
  • incubation period = 7-10d, more than 50% of cases occur in adolescents and adults - serve as a reservoir for infxn of infants and children
  • sxs:
    • catarrhal stage (1-2wk): insidious onset of sneezing, rhinorrhea, loss of appetite, malaise, hacking cough at night (most infxs state)
      • signs: gagging, cyanosis, inc work of breathing, sweating
    • paroxysmal stage (2-8wk): spasms of rapid coughing fits during expiration followed by deep, high-pitched inspiratory “whoop”, last several minutes, posttussive emesis or syncope
    • convalescent stage: dec in frequency and severity of paroxysms, begins 4wk after onset of cough and lasts several wks
25
Q

pertussis dx and tx

A
  • dx: most accurate during catarrhal phse, dx mostly clinical (cough >2wk required), microbiological testing required to ocnfirm; culture and PCR assays if cough for 2-4wk, cx = GOLD STANDARD, must use dacron or calcium alginate swab to obtain from posterior nasopharynx; serology = alternative to cx for cough after 4+wk, WBC count = elevated, lymphocytosis
  • tx: abx during catarrhal phase (dec severity and duration of cough, indicated for cough <3wk or 6wk for preg women, health care workers, or child care workers)
    • macrolides (azithro, clarithro, erythro)
    • macrolide intolerant (bactrim DS, ampicillin)
  • prophylaxis: single Tdap booster for adults 16-64y, postexposure prophylaxis for close contacts
  • complications: infxn (PNA, otitis media)
26
Q

pertussis tx based on age

A
  • infants <1mo: azithro x5d, erythro (both are associated with inc risk hypertrophic pyloric stenosis)
  • infants and children >1mo: azithro x5d, clarithro x7d
  • children >2mo: macrolides, bactrim
27
Q

esophagitis (esophageal candidiasis)

A
  • immunosuppressed pts with AIDS, solid organ transplants, leukemia, and lymphoma
  • MC pathogens: candida albicans, herpes simplex, CMV
  • sxs: 1 or more (odynophagia, dysphagia, oral thrush, retrosternal or epigastric pain, N/V)
  • signs: normal oral mucosa
  • dx: endoscopy with bx and brushings
  • tx: empiric - fluconazole, ganciclovir (CMV), HAART (AIDS), sxatic tx for herpes
28
Q

oral candidiasis (thrush)

A
  • RF: HIV, dentures, DM, exposure to broad spectrum abx, or inhaled steroids
  • sxs: sore and painful, dry mouth, burning mouth or tongue, dysphagia, unpleasant taste
  • signs: thick, whitish patches on oral mucosa (easily rubbed off), diffuse erythema
  • dx: KOH prep (pseudohyphae or hyphae)
  • tx: clotrimazole troches (topical), nystatin, PO fluconazole
29
Q

cryptococcosis (PNA)

A
  • MCC: cryptococcus neoformans serotype A (AIDS), cryptococcus gattii; encapsulated budding yeast found in soil contaminated with dried pigeon dung, cockroaches, or bird droppings
  • transmission: inhalation, common in immunocompromised and solid organ transplant hosts, MC areas for infxn = lungs and CNS; CD4 <100 if AIDS
  • sxs: hx pulm dz if COPD, steroid use, posttransplant, fever (low grade - MC in HIV), productive cough, dyspnea, HA, wt loss, pleuritic chest pain, malaise
  • signs: pleural effusions, LAD
  • complications: meningitis, meningoencephalitis
  • dx: CXR (solitary or mult nodules, granulomas, patchy pneumonitis), india ink (confirms, CSF - variable pleocytosis mostly lymphocytes, inc opening pressure, inc protein, dec gluc), cx of BAL; cx = budding, encapsulated fungus; CSF = crypt antigen; CT or MRI
  • tx: obs only if CSR nl, CSF cx or other tests (-), urine cx (-), lesion small, stable, or shrinking, no predisp conditions for dissem
    • PO fluconazole, if severe = amphotericin B, +/- flucytosine
30
Q

histoplasmosis etiology, RF, and sxs

A
  • fungal infxn MC associated with spelunkers, bat droppings, chicken coops - infxn of lung leading to granuloma formation
  • histoplasma capsulatum (dimorph fungus with septate hyphae), Ohio and Mississippi river valleys
  • RF: AIDS CD4 <150, use of steroids, hematologic malig, solid organ transplant
  • sxs: 90% asxatic, flu-like sxs, F, HA, malaise, myalgia, abd pain, chills, severe SOB, worsening cough, hemoptysis, CP, jnt pain, skin lesions, wt loss, D, abd pain, periph edema, angina, confusion, szs, AMS
  • signs: erythema nodosum, erythema multiforme, arthritis, HSM, hilar and mediastinal nodes, rales/wheezes, hypoxemia, pericardial rubs, abd mass, intestinal ulcers, CN deficits, meningismus, mm weakness, ataxia
31
Q

histoplasmosis dx and tx

A
  • dx: urine and serum ag testing (cross reactivity with blastomyces and coccidiodes = false +), BAL ag testing, pancytopenia, AST/ALT elevated, LDH elevated, sputum cxs, blood cxs, abx (anti-H = active, anti-M = chronic), complement fixing Ab
    • Imaging: CXR (hilar and mediastinal nodes (coin lesions), cavitation in upper lobes, CT look for adrenal involvement, echo TEE or TTE if valvular involvment suspected, LB
  • tx: acute asxatic = no tx; acute sxatic = PO itraconazole x 3mo, amphotericin B for severe or immunocompromised host
32
Q

pneumocystis PNA

A
  • pneumocystis jiroveci - caused by fungus found in lungs of mammals, MC opportunistic infxn in HIV/AIDS
  • sxs: F, SOB, nonproductive cough, exam findings disproportunate to imaging, showing diffuse interstitial infiltrates, fatigue, weakness, wt loss
  • dx: CXR (definitive - diffuse or perihilar infiltrates, reticular interstitial PNA or airspace dz that mimics pulm edema), sputum wright-giemsa stain or DFA, BAL, CD4 <200 if AIDS, ABG hypoxia, hypocapnia, reduced DLCO, LDH inc but nonspecific, serum B-glucan, WBC low
  • tx: BACTRIM, add roids if PaO2 <70, dapsone if sulfa allergy
  • all pts with CD4 <200 should undergo prophylaxis (bactrim)
33
Q

botulism

A
  • clostridium botulinum, results from ingestion of preformed toxins produced by spores
  • source: improperly stored food (home canned goods), inactivated by cooking food at high temps (212F x10mins), wound contamination
  • sxs: GI sxs (abd cramps, N/V/D), hallmark is symmetric descending flaccid paralysis starting with dry mouth, double vision, ptosis, and/or dysarthria, paralysis of limb musculature (late), resp distress leading to death
  • dx: c. botulinum toxin in serum, stool, gastric bioassay
  • tx: admit pt and observe resp status (gastric lavage only in first few hours), if high suspicion administer antitoxin, contaminated wounds = wound cleansing and PCN
34
Q

diphtheria

A
  • corynebacterium diphtheria
  • transmission: resp secretions; produces EXOTOXIN causing myocarditis and neuropathy
  • sxs: nasal infxn/discharge, laryngeal infxn, pharyngeal infxn (tenacious gray membrane covering tonsils and pharynx, mild sore throat, fever, malaise, myocarditis, neuropathy involving cranial nerves
  • dx: cx to confirm, but CLINICAL dx
  • tx: horse serum antitoxin from CDC, if airway obst remove via laryngoscopy, PCN or erythromycin, diphtheria toxoid as vaccine (DTaP) or Td
35
Q

tetanus

A
  • neurotoxins produced by spores of clostridium tetani, a gram pos anaerobic bacillus (proliferates producing exotoxin in contaminated wounds)
  • RF: incomplete or no tetanus IMZ
  • sxs: hypertonicity and contraction of masseter mm - trismus or lockjaw, progresses to severe, generalized muscle contractions, risus sardonicus = grin dt contraction of facial muscles, opisthotonos = arched back dt contraction of back mm, sympathetic hyperactivity
  • dx: clinical, obtain wound cx but unreliable
  • tx: admit to ICU, resp support, diazepam for tetany, neutralize unbound toxin with passive IMZ, give single IM dose of tetanus immune globulin (TIG)
36
Q

toxoplasmosis etiology, RF, sxs

A
  • organism: toxoplasma gondii (obligate intracellular)
  • active infxn in immunocomp hosts are dt the release of encysted parasites that undergo rapid transformation into tachyzoites within CNS and are not contained by the immune system
  • definitive host: cat (feces) - infects birds, rodents, grazing animals (lamb, pork), humans
  • transmission: oral (ingestion of contaminated soil, food, water), by blood or organs, transplacental, lamb, beef, pork, cat litter box
  • MC space occupying lesion in HIV-infected pts
  • sxs: cervical LAD (MC - nontender, discrete, firm), HA, malaise, fatigure, fever, myalgia, sore throat, abd pain, maculopap rash, meningoencephalitis, confusion, encephalitis (AMS, F, szs, HA, focal neuro findings, motor def, CN palsies, mvmt disorders, dysmetria, visual-field loss, and aphasia
  • complications: PNA, myocarditis, encheph, pericarditis, polymyositis
37
Q

toxoplasmosis dx and tx

A
  • clinical dx in AIDS pt, serum IgG and IgM (acute) abs to toxoplasma (IgG detected 2-3wks, IgG levels precede encephalopathy), double dose contrast CT head (multiple peripheral ring-enhancing lesions usually in basal ganglia), MRI w/ contrast, brain bx to ro primary CNS lymphoma, labs
    • CD4 <100 if AIDS, lymphocytosis, ESR high, AST/ALT high, CSF elevated ICP, mononuc pleuocytosis, inc protein and gamma globulin level
  • tx: recheck serum IgM in 3wk, enceph treat = pyrimethamine AND sulfadiazine OR clinda, spiramycin
    • bactrim DS daily is PROPHYLAXIS
38
Q

Rocky Mountain Spotted Fever

A
  • southeast, midwest, western US, spring and summer, intracellular bacteria rickettsia rickettsii
  • transmission: vector-borne (dog ticks)
  • sxs: onset sxs within 1 wk after bite, sudden onset F, chills, HA, photophobia, N/V, malaise, myalgias, papular rash (begins peripherally - wrists, forearms, ankles - and spreads centrally to rest of limbs, trunk, and face), becomes maculopapular - (nonblanching petechial rash
    • may lead to interstitial pneumonitis, resp failure, and/or CNS involvement
  • dx: elevated LFTs, thrombocytopenia, acute and convalescent serology, immunofluorescent staining of skin bx
  • tx: doxy x7d, if preg or CNS manifestations tx with chloramphenicol
39
Q

cytomegalovirus

A
  • human herpesvirus type 5, dsDNA virus, HIV or posttransplant, CD4 <50, asxatic - latent - reactivates
  • RF: daycare, blood transfusions, mult sex partners, CMV mismatched organs or BMT
  • transmission: person-person, placenta, blood trans, organ trans, breast milk, sex
  • sxs: most asxatic, flu-like, F, malaise, myalgias, arthralgias (appears like mono)
  • signs: fine crackles, LAD, +/- pharyngitis, HSM
  • complications: esophageal ulcers (CD4 <100), encephalitis (AMS), peripheral polyradiculopathy, retinitis (CD4 <50)
  • dx: ag test (CMV pp65 in WBCs), qualitative PCR in blood and tissue, labs (lymphocytosis or leukopenia, LFTs elevated)
    • cx: difficult, antigens in blood, urine, CSF via PCR
    • BAL positive for CMV, tissue bx (owl’s eyes, intracytoplasmic inclusions), CXR consistent with pneumonia
  • tx: healthy without sxs = no tx; immunocompromised = CMV immunoglobulin and IV ganciclovir
    • AE = fever, rash, D, heme effects
  • prophylaxis: bactrim if CD4 <50
40
Q

rabies

A
  • devastating, deadly viral encephalitis, contracted from a bit or scratch by infected animal; infxn from corneal transplant as well; more prominent in developing countries where rabies vaccination is not widespread
  • sxs: once sxs present can be fatal - pain at site of bite, prodromal sxs of sore throat, fatigue, HA, N/V, encephalitis (confusion, combativeness, hyperactivity, fever, seizures), hydrophobia, ascending paralysis
  • dx: virus or viral ag form infxed tissue or saliva, 4x inc in serum ab titers, negri bodies, PCR detection of viral RNA
  • tx: clean wound thoroughly, wild animal bits - send animal for immunofluorescence of brain tissue; if healthy animal - capture, place in observation x10d
  • known rabies: passive IMZ (human rabies IG 40units into wound and gluteal region), active IMZ (human diploid cell rabies (HDCV) vaccine in 3 IM doses into deltoid or thigh over 28d
41
Q

varicella (herpes zoster)

A
  • age >50yo, caused by reactivation of variceclla-zoster virus, which is dormant in the dorsal root ganglia and reactivated during stress, infxn, or illness; occurs only in pts who have had chickenpox, contagious when open vesicles present and immunocompromised
  • sxs: severe pain and rash in dermatomal distrib (pain before rash - thorax MC and trigeminal distrib), vesicles = pustular on d3-4, crust over by 7-10d
  • signs: grouped vesicles on erythematous base
  • complications: postherpetic neuralgia, excruciating pain persisting after lesions have cleared and does not respond to analgesics, uveitis, meningoencephalitis, deafness
  • dx: tzanch smear, cx of vesicular fluid, varivax indicated for indiv >1yo, zostavax for prevention of zoster in pts who have no CIs
  • tx: keep lesions dry/clean, analgesics for pain, local triam in lidocaine, antivirals (acyc, famcic, valavyc reduce incidence of PHN, reduce pain, dec length of illness), roids to dec incidenc of PHN, live vaccine (varizig) to reduce severity and duration

R5 - Internal Medicine (10 decks)

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