USMLE STEP 1 PRACTICE
QUESTIONS AND CORRECT/ 100%
VERIFIED ANSWERS GRADE A+
LATEST UPDATED!!
Af38-year-
oldfmanfpresentsftofthefemergencyfdepartmentfdueftofseizuresfthatfstartedfearlierfthatfday,fasfreportedfbyf
hisfsister.fHefaddsfthatfhisfvisionfisfalsofblurry.fThefpatientfsaysfhefhasfneverftraveledfoutsidefoffthefUnitedfS
tates.fPhysicalfexaminationfrevealsfseveralfenlargedfcervicalflymphfnodesfasfwellfasfafrightfhomonymousfhe
mianopia.fLaboratoryfstudiesfshowfafCD4fcountfoff78fcells/μL.fThefpatientfisfsentfforfanfMRIfwithfring-
enhancingflesion.f-fCORRECTfANSWER-ToxoplasmafGondii
OccursfinfpatientsfwithfHIVfwhosefCD4fcountfisf<100fcells/μL.fItfmostfcommonlyfmanifestsfwithfencephalitis
fcharacterizedfbyfseizuresfand/orffocalfneurologicfdeficits.fThefclassicfpicturefonfafCTfscanforfanfMRIfoffthefh
eadfisfafring-
enhancingflesionfwithfsurroundingfedemafandfmassfeffectf(asfshownfinfthisfMRI).fThefspecificfvisualffieldfde
fectfinfthisfpatientfisfdueftofthefcerebralflesionsfcausingfaffocalfneurologicfdeficit.
New-onsetfseizuresfinfanfHIV-
positivefpatientfwithfafCD4fcountf<100fcells/µLfisfhighlyfsuggestivefofftoxoplasmosis.fOtherfmanifestationsf
arefchorioretinitis,fwhichfisfcharacterizedfbyfeyefpainfandfdecreasedfvisualfacuity,fasfseenfinfthisfpatient.
Af34-year-oldfmanfpresentsftofthefemergencyfdepartmentfwithfafdryfcough,flow-
gradeffevers,fandfdifficultyfbreathingfthatfbecomesfprogressivelyfworsefwithfexertion.fHefsaysfthatfhefhasfh
adfthesefsymptomsfforfthefpastf2-
3fweeks.fHefreportsffeelingfincreasinglyffatiguedfandfhasfhadfanfunintentionalfweightflossfoff10fpoundsf(4.5f
kilograms)finfthefsameftimefperiod.fThefpatientfdeniesfanyfalcohol,ftobacco,forfillicitfdrugfusefbutfadmitsftof
havingfhadfmultiplefsexualfpartnersfwithoutfusingfprotection.fThefpatient'sftemperaturefisf38.1oCf(100.6oF
),fbloodfpressurefisf102/72fmmfHg,fpulsefisf96/min,frespiratoryfratefisf22/min,fandfSpO2fisf86%fonfroomfair.f
Physicalfexaminationfshowsforalfthrush,fbilateralfralesfatftheflungfbases,fandfrightfaxillaryfandfleftfinguinalfl
ymphadenopathy.f-fCORRECTfANSWER-InhibitionfoffFolatefSynthesis
Thisfpatientfpresentsfwithffever,fdyspneafonfexertion,fandfunintentionalfweightfloss,fwhichfarefsuggestivefo
ffpneumonia.fHefalsofhasfafhistoryfoffunprotectedfsexfwithfmultiplefpartners,fandfpresentsfwithforalfthrushf
andfinguinalflymphadenopathy,fwhichfarefsuggestivefoffHIV.fTakenftogether,fthefpatient'sfpresentationfan
dfhistoryfraisefsuspicionfoffanfopportunisticfinfection,fsuchfasfPneumocystisfjiroveciif(PCP)fpneumonia.fPCPf
pneumoniafisfanfAIDS-
definingfillnessfandfisftypicallyfseenfinfpatientsfwithfCD4fcountsf<200fcells/mm.fP.fjiroveciifisfanfascomyceto
usffungifthatfalsofcausesfpneumoniafinfhematopoietic-cellfandfsolid-
organftransplantfrecipients,fcancerfpatients,fandfpatientsfreceivingfglucocorticoids,fchemotherapeuticfage
QUESTIONS AND CORRECT/ 100%
VERIFIED ANSWERS GRADE A+
LATEST UPDATED!!
Af38-year-
oldfmanfpresentsftofthefemergencyfdepartmentfdueftofseizuresfthatfstartedfearlierfthatfday,fasfreportedfbyf
hisfsister.fHefaddsfthatfhisfvisionfisfalsofblurry.fThefpatientfsaysfhefhasfneverftraveledfoutsidefoffthefUnitedfS
tates.fPhysicalfexaminationfrevealsfseveralfenlargedfcervicalflymphfnodesfasfwellfasfafrightfhomonymousfhe
mianopia.fLaboratoryfstudiesfshowfafCD4fcountfoff78fcells/μL.fThefpatientfisfsentfforfanfMRIfwithfring-
enhancingflesion.f-fCORRECTfANSWER-ToxoplasmafGondii
OccursfinfpatientsfwithfHIVfwhosefCD4fcountfisf<100fcells/μL.fItfmostfcommonlyfmanifestsfwithfencephalitis
fcharacterizedfbyfseizuresfand/orffocalfneurologicfdeficits.fThefclassicfpicturefonfafCTfscanforfanfMRIfoffthefh
eadfisfafring-
enhancingflesionfwithfsurroundingfedemafandfmassfeffectf(asfshownfinfthisfMRI).fThefspecificfvisualffieldfde
fectfinfthisfpatientfisfdueftofthefcerebralflesionsfcausingfaffocalfneurologicfdeficit.
New-onsetfseizuresfinfanfHIV-
positivefpatientfwithfafCD4fcountf<100fcells/µLfisfhighlyfsuggestivefofftoxoplasmosis.fOtherfmanifestationsf
arefchorioretinitis,fwhichfisfcharacterizedfbyfeyefpainfandfdecreasedfvisualfacuity,fasfseenfinfthisfpatient.
Af34-year-oldfmanfpresentsftofthefemergencyfdepartmentfwithfafdryfcough,flow-
gradeffevers,fandfdifficultyfbreathingfthatfbecomesfprogressivelyfworsefwithfexertion.fHefsaysfthatfhefhasfh
adfthesefsymptomsfforfthefpastf2-
3fweeks.fHefreportsffeelingfincreasinglyffatiguedfandfhasfhadfanfunintentionalfweightflossfoff10fpoundsf(4.5f
kilograms)finfthefsameftimefperiod.fThefpatientfdeniesfanyfalcohol,ftobacco,forfillicitfdrugfusefbutfadmitsftof
havingfhadfmultiplefsexualfpartnersfwithoutfusingfprotection.fThefpatient'sftemperaturefisf38.1oCf(100.6oF
),fbloodfpressurefisf102/72fmmfHg,fpulsefisf96/min,frespiratoryfratefisf22/min,fandfSpO2fisf86%fonfroomfair.f
Physicalfexaminationfshowsforalfthrush,fbilateralfralesfatftheflungfbases,fandfrightfaxillaryfandfleftfinguinalfl
ymphadenopathy.f-fCORRECTfANSWER-InhibitionfoffFolatefSynthesis
Thisfpatientfpresentsfwithffever,fdyspneafonfexertion,fandfunintentionalfweightfloss,fwhichfarefsuggestivefo
ffpneumonia.fHefalsofhasfafhistoryfoffunprotectedfsexfwithfmultiplefpartners,fandfpresentsfwithforalfthrushf
andfinguinalflymphadenopathy,fwhichfarefsuggestivefoffHIV.fTakenftogether,fthefpatient'sfpresentationfan
dfhistoryfraisefsuspicionfoffanfopportunisticfinfection,fsuchfasfPneumocystisfjiroveciif(PCP)fpneumonia.fPCPf
pneumoniafisfanfAIDS-
definingfillnessfandfisftypicallyfseenfinfpatientsfwithfCD4fcountsf<200fcells/mm.fP.fjiroveciifisfanfascomyceto
usffungifthatfalsofcausesfpneumoniafinfhematopoietic-cellfandfsolid-
organftransplantfrecipients,fcancerfpatients,fandfpatientsfreceivingfglucocorticoids,fchemotherapeuticfage
