Step 3 Kaplan Ch1-1 Infectious Disease

Staphylococcus Aureus.

CONDM/1st gen Cephalo: Cloxacillin, Oxacillin, Nafcillin, Diclox, Methacillin/ Ceflexin, Cefazolin

TMP/SMX, clindamycin

Vanco/telavancin, linezolid, daptomycin, tigercycline

Cephalo is still safe

Macrolides or Clindamycin

Vanco/telavancin, linezolid, daptomycin, tigercycline

Macrolides, TMP/SMX, Clindamycin

LINES lymphangitis, impetigo, necrotizing fascitis, erysipelas, scarlet fever

Use any of the "Staph Tx" to cover both. Specific for strep is penicillin, ampacillin, amoxicillin.

E. coli, Enterobacter, Citrobacter, Morganella, Pseudomonas, Serratia

Cefepime, Ceftazadime, pipercillin ticarcillin, aztreonam, cipro/levo/gati/moxi, gentamicin, tobramycin, amikacin, imipenem, meropenem, ertapenem

Ertapenem

Pipercillin and Ticarcillin

Levofloxacin, gemifloxacin and moxifloxacin

aminoglycosides

carbapenems

tigecycline

Metronidazole, Carbapenems, Pipercillin, Ticarcillin, Cefoxitin, Cefotetan

Clindamycin is the best medication for anaerobic strep.

Aminoglycosides, Aztreonam, Fluoroquinolones, Oxacillin/Nafcillin, Cephalosporins (except cefoxitin and cefotetan)

Red man syndrome, from histamine release. Slow the rate of infusion.

Acyclovir, Valacyclovir, Famciclovir

Valganciclovir, ganciclovir, foscarnet. Valganciclovir for tx of CMV retinitis.

Foscarnet

Valganciclovir and Ganciclovir

Ribivarin and Interferon 2 alpha

Ribivarin

lamivudine, interferon, adefovir, tenofovir, entecavir, telbivudine

Fluconazole

Fluconazole

Voriconazole, covers all candida and is best for aspergillus.

Echinocandins (Caspofungin, Micafungin, Anidulafungin) does not cover cryptococcus

Echinocandins, the reason they do not cause many side effects

Amphotercin

shake and bake, renal toxicity, hypokalemia, metabolic acidosis. Fever shakes and chills.

periosteal elevation, may show up negative and take up to 2 weeks for bone change to present in the xray.

peripheral vascular disease or diabetes

plain xray, second line MRI if x ray is negative. most accurate is bone biopsy and culture.

MRI

Sedimentation rate.

Direct contiguous spread from overlying tissue.

equal sensativity , MRI is far more specific

if ESR stays elevated after 4-6 weeks of therapy.

Staphyloccous is MC bug, therefor IV Oxacillin/Nafcillin is MRSA do vancomycin, linezolid, daptomycin.

can give oral abx

must confirm bone biopsy, follow ESR

Non, obtain biopsy and treat what you find.

Otitis externa, cellulitis of the skin of the external auditory canal. associated with swimming and foreign objects in the ear.

topical abx, ofloxacin or polymixin/neomycin. add topical hydrocortisone, acetic acid and water solutions.

Malignant otitis externa, osteomyelitis of the skull!! from psuedomonas tx as osteomyelitis. Initial test: skull xray or MRI, most accurate is a biopsy.

surgical debridement, antibiotics active against pseudomonas Pipercillin, cefipime, carbapenem, aztreaonam

Otitis Media, no radiologic test needed. Tx Amoxicillin 7-10days, review in 3 days if no improvment switch to Cefdinir, Cefuroxime, Cefprozil, Cefpodoxime.

Tympanocentesis and aspirate of the tympanic membrane.

Sinusitis, most viral. S. Pneumoniae, H. influenzae, M. catarrhalis. Diagnostic test, X-ray MRI or CT most accurate is aspirate for culture.

Same as otitis media, use amoxicillin if pain and fever, persistent symptoms despite 7 days of decongestants, and purulent nasal discharge.

Pharyngitis, best initial dx test: rapid strep test. Neg? No further testing or treatment with abx. Most accurate test is culture. Tx penicillin or amoxicillin, allergy use azithromycin or clarythromycin

Influenza, next best viral antigen detection. Tx oseltamivir or zanamivir if patient presents within first 48 hrs after the onset of symtoms

>50yo, COPD, CHF, dialysis px, steroid use, healthcare worker

Impetigo, Strep pyogenes or staph aureus. Tx topical mupirocen or retapamulin, severe give oral dicloxacillin or cephalexin. Community aquired MRSA: TMP/SMZ severe with anaphylxis Vancomycin or Linezolid or Daptomycin

Erysipelas, group A strep pyogenes of the skin. Next step: blood cultures treat with oral dicloxacillin or cephalexin. Group A beta hemolytic streptococci treat with penicillin VK.

NO, only glomerulonephritis. Pharyngitis can lead to glomerulonephritis and heart, rheumatic fever.

Cellulitis, if on leg do a lower extremity doppler to exclude blood clot both can cause fever. Staph aureus and strep pyogenes tx minor: dicloxacillin, cephalexin severe: Oxacillin, nafcillin or cefazolin.

Only difference is size, leading up to abcess. Staph Aureus related infection Tx same as cellulitis: Dicloxacillin, Cephalexin, Severe: Oxacillin, Nafcillin, Cefazolin IV.

Fungal infections, Initially do a KOH preparation. Tx Topical antifungal medication: Azole, Nystatin or ciclopirox, Oral for scalp or nails: Terbinafine (increased LFT), Intraconazole, Griseofulvan (has lest efficacy)

Discharge positive urethritis, no discharge cystitis. Best initial test: urethral swab or nucleic acid ampliflication. Tx: Gono: Ceftriazone IM or Ciprofoxacin Chlamydia Azythromycin or Doxycycline. Pregnant Ceftriaxone and Azithromycin.

Terminal compliment dificiency. Recurrent episodes of Neiseria including genital and CNS infections.

Cervicitis, do a swab of discharge. Tx as you would urethritis.

PID, no specific blood tests. CBC-leukocytosis (measure severity) Best initial test: pregnancy, cervical cultura, DNA probe for Chlamydia and Gono. Most accurate: Laparoscopy (only for persistent or recurrancy). Tx: Outpatient ceftriaxone IM and doxycycline O Inpx: Cefoxitin IV and Doxycycline and Metronidazole

PAACE: Penicillins Azythromycin Aztreonam Cephalosporins Erythomycin

Epidydimo Orchitis, Tx <35 Ceftriaxone/Doxycycline >35 Fluoroquinone

All associated with enlarged lymph nodes. Sexual history not important as presence of ulcer.

Chancroid, H. DuCREYI best initial test swab for gram stain (gram negative coccocbacilli and culture: Nairobi medium or Mueller Hinton agar. Tx Ceftriaxone or single dose Azithromycin

Lymphogranuloma venereum. Do serology for Chlamydia Trachomatis. Aspirate the bubo. Tx with doxycycline.

If clear vesicular lesions no diagnostic test needed. Next best step would be to tx with acyclovir, valcyclovir or famciclovir for 7-10 days. Recurrent do daily suppressive therapy. If unclear do a tzanck prep.

Darkfield microscopy, VDRL and RPR are only 75% sensative. (25% false neg rate)

Primary Syphilis tx single IM shot of penicillin, or use doxycycline

Secondary Syphilis, do a RPR or FTA tx singel IM shot of penicillin or doxycycline

Tertiary Syphilis, do RPR or FTA, then a lumbar puncture and test CSF for VDRL and FTA. Tx IV penicillin if allergic desensatize.

Darkfield microscopic exam.

desensitization

Granuloma Inguinale, "biopsy or "touch prep" tx is doxycycline or TMP/SMX

Pediculosis capitis (Pedicularis humanis capitis), unknown to be vectors of disease tx permethrin or lindane

Pediculosis Corporis (Pediculus humanis corporis)know vecros of louse-born typhus (Richettsia prowazeki), trench fever (Rochalimaea quintana) and louse-borne relapsing fever (Borrellia recurrentis)

Pediculosis pubis (Pthirus pubis) tx with permethrin or lindane

scrape and magnify for scabies, tx with permethrin lindane

Cystitis, do urinalysis, most accurate is a urine culture. Tx for uncomplicated is TMP/SMX for 3 days if resistance in e coli is >20% in that area use Ciprofloxacin or Levofloxacin

7 days TMP/SMX or Ciprofloxacin, compicated means the presence of a stone, anatomical abnormality, stricture, tumor or obstruction.

Treat for 3 days. If male do ultrasound looking for anatomical abnormality.

Only treat in pregnant women, do nothing if not pregnant.

Pyelnephritis, do a urinalysis and culture. Is this patient IN or OUT? IN: Ampicillin/Gentamicin. OUT: Ciprofloxacin

Infections

Numerous suggest an improper specimen collection

Indirect evidence of infection

Presence of gram negative bacteria

Nonspecific in urinalysis

Nonspecific as well

Sonogram or CT of kidneys to find collection. Most accurate is a biopsy. Tx with quinolone and ADD staphlococcal coverage (Nafcillin/Oxacillin). "she's already been on gram negative therapy for a while and it is not getting better, think about Staph. YOU ARE OBVIOUSLY NOT TREATING THE BUG OR THE DZ. GET OUT OF THE BOX.

Prostatitis, treat with ciprofloxacin for an extended period of time, use the same drugs as pyelonephritis but extend the length of therapy.

1) Two positive blood cultures (Staph aureus, Strep viridians/bovis/enerococci, gram neg rods, or candida) 2) Abnormal echocardiogram: (intracardiac mass, vegetations, abcess, partial dehiscence of prosthetic valves)

HACEK - Haemophilus aphrophilus, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae.

Fever (>38'C) Risk Factors, Vascular findings, Immunological findings, Microbiologic findings, Microbiotic findings

IV drug user, presence of structural heard disease, prosthetic heart valve, dental procedures involving bleeding, history of endocarditis.

Janeway lesions, septic pulmonary infarcts, arterial emboli, mycotic aneurysm, conjunctival hemorrhage

Roth spots, Osler's nodules, Glomerulonephritis

Positive blood culture but does not meet major criteria

2 major 5 minor. Diagnosis made by presence of 2 major, 1 major and 3 minor, 5 minor criteria

Prosthetic heart valve, injection drug user, dental procedure that cause bleeding, previous endocarditis, unrepaired or recently repaired cyanotic heart disease.

DO BLOOD CULTURES first if positive then do echocardiogram look for vegitations. IF Transthoracic Echo (60% sensative) is negative do Transesophageal Echo (~95% sensative). First find the cause then the location.

Retina

flat, painless in hands and feet

raised, painful, and pea shaped

under fingernails

Vancomycin with Gentamicin for 4-6 weeks most common bugs covered. Fungi and resistant gram negative rods are not covered.

Colonoscopy, cancer related.

Surgery, valve replacement

Prosthetic valves, unrepaired cyanotic heart disease, previous endocarditis, transplant recipients who develop valve disease.

Dental procedures that cause bleeding (amoxicillin or clindamycin) Respiratory tract surgery, Surgery of infected skin.

-CD4 <500 -symptomatic patient with any CD4 count or viral load -pregnant woman -needle stick scenario, where patient is known to be HIV positive.

1) tenofovir, emtricitabine, efavirenz (single pill) 2) zidovudine, lamivudine, efavirenz 3) zidovudine, lamivudine, ritonavir/lopinavir

Lactic Acidosis, zidovudine, lamivudine, tenofovir, emtricitabine, didanosine, stavudine, abacavir

anemia

pancreatitis and peripheral neuropathy

pancreatits and neuropathy

none

rash

Hyperglycemia and hyperlipidemia. All PI's end in "avir"

kidney stones

no major AE's. Efavirenz and Nevirapine "Never Ever"

HAART for a month, if any exposure to HIV positive blood (needle, scalpel or penetrating injury) or after unprotected sexual contact with a person known to be HIV positive.

keep her on the same therapy

CD4 <500: start HAART. CD4 >500 and viral load is low: Use HAART during second and third trimester to prevent perinata transmission.

<200 CD4 TMP/SMX is the best, if a rash is caused then switch to atovoquone or dapsone (dapsone cannot be used if there is G6PD). Aerosolized pentamidine has the poorest efficacy.

<50 CD4 and use azythromycin once a week orally.

Pneumocystis Jiroveci Pneumonia, do a chest Xray look for interstitial markings bilaterally, most accurate is a bronchoalveolar lavage. Tx IV TMP/SMX. Atovoquone for mild pneumocystis. Steroids if PCP is severe (pO2 <70 or A-a gradient >35) then give steroids.

Toxoplasmosis, do a head CT with contrast "ring". Tx with pyimethamine and sulfadiazine for 2 weeks and repeat CT scan. If lesions unchanged perform brain biopsy looking for lymphoma.

Cytomegalovirus, perform a dilated ophthalmologic examination. CMV diagnosed by the appearance of these lesions. Tx with ganciclovir or foscarnet. Maintenance therapy with oral valganciclovir, unless CD4 goes up.

Cryptococcus, perform a lumbar puncture (increased lymphocytes) and do an India ink stain (60% sensative), most accurate is a cryptococcal antigen test. Treat initially wiht amphotericin, followed by fluconazole. Continue fluconazole lifelong unless CD4 rises.

If CD4 rises you can stop all prophylaxis tx, but you cannot stop antiretrovirals.

Progressive Multifocal Leukoencephalopathy (PML) best initial test is a head CT or MRI. (no ring enhancing lesions and no mass effect). Tx: no specific therapy, once CD4 rises this will resolve.

Mycobacterium Avium Intracellulare. Anemia shows bone marrow involvment. Increase Alkphos and GGTP show hepatic involvment. Diagnose with a Liver biopsy>Bone Marrow biopsy>Blood Culture. Tx is with clarithromycin and ethambutal.

Leptospirosis, spirochete.

Leptospirosis do a serology screening, if left untreated will progress to altered mental status, tx with ceftriaxone or penicillin.

Tularemia gram negative, diagnose with serology (DO NOT TAKE A CULTURE, spores will infect lab personel and give Pneumonia). Tx with DOC streptomycin or amikacin or gentamicin.

Cysticercosis, tx with albendazole.

Doxycycline, rash suggestive of lyme is enought to warrant treatment. If rash is not seen, do serology first.

Lyme "erythema migrans". next step is serology, complications involve joints cardiac or neurlogical funcion. MC late manifestation is joint involvment, MC cardiac: AV conduction block/defect MC: neurologic: 7th cranial nerve palsy (Bell's Palsy). Tx with oral doxycycline or amoxicillin. CNS/Cardiac involvement: IV ceftriaxone.

Babesiosis, do a peripheral blood smear (tetrads of intraerytrhocyctic ring forms) or a PCR. Tx with clindamycin and quinine.

Ehrlichia, do a peripheral blood smear looking for inclusion bodies in WBC called "morulae". Or a PCR. Tx with doxycycline.

Malaria, do a blood smear. Tx: Acute disease give quinine and doxycycline.

Mefloquine (weekly) (AE: neuropsychiatric, sinus bradycardia and QT proongation) or atovoquone/proguanil (Malarone/daily).

Nocardia, do a chest Xray followed by a culture (branching, gram positive filaments, weakly acid fast). Nocardia can deseminate to any organ, skin and brain are most common. Tx with TMP/SMX

Actinomyces, do a gram stain and anaerobic culture (gram positive, branching filamentous bacteria). Tx with high dose penicillin.

Histoplasmosis, do serology/culture/PCR. Disseminated disease can enter bone marrow and cause pancytopenia. Tx: Acute pulmonary disease is transient and requires no therapy. Disseminated dx is treated with amphotericin.

Coccidioidomycosis, tx with itraconazole.

Blastomycosis, bone lesions are common. tx with amphotericin or itraconazole

Galactomannan test