Infectious & Dermatology Flashcards
Historical and physical “red flags” in a patient with an unknown rash
<ul><li>Fever</li><li>Toxic appearance</li><li>Hypotension</li><li>Mucosal lesions</li><li>Severe pain</li><li>Very old or young age</li><li>Immunosuppressed</li><li>New medication</li></ul>
DDX of Petichiae
Palpable:<br></br> Vasculitis<br></br> Infection<br></br>Non-palpable:<br></br> Low plt (ITP, DIC)
DDx of petichiae in a febrile patient:
<b>Palpable:</b><br></br> Meningococcemia<br></br> Disseminated GC<br></br> Endicarditis<br></br> RMSF<br></br> HSP<br></br><br></br><b>Non-palpable:</b><br></br> Purpura fulminans<br></br> DIC<br></br> TTP
DDx of erythematous Rash
Staphylococcal scalded skin syndrome<br></br>Toxic epidermal necrolysis<br></br>Toxic shock syndrome<br></br>Kawasaki dis<br></br>Anaphylaxis<br></br><br></br>Other DDx:<br></br>Scarlet fever<br></br>Alcohol flush<br></br><br></br>
<strong>Approach to the maculopapular rash</strong>
<b>Febrile/Toxic & Central:</b><br></br>Erythema migrans (Lyme dis)<br></br>Viral exanthem (measles, rubella)<br></br><br></br><strong>Febrile/Toxic & Peripheral:<br></br></strong>Erythema multiforme<br></br>Stevens-Johnson Syndrome<br></br>TEN<br></br><br></br><strong>Afebrile/Nontoxic:<br></br></strong>non life threatening<br></br>Drug reaction<br></br>Pitryasis<br></br>Scabies<br></br>Eczema<br></br>Psoriasis
<strong>Approach to the vesiculobullous rash</strong>
<b>Febrile and Diffuse:</b><br></br>Varicella<br></br>Smallpox<br></br>Disseminated GC<br></br>DIC<br></br><br></br><strong>Febrile and localized</strong>:<br></br>Necrotizing fasciitis<br></br>Hand foot mouth dis (Coxackie A)<br></br><br></br><strong>Afebrile and Diffuse:<br></br></strong>Bollous pemphigoid<br></br>Pemphigus vulgaris<br></br><br></br><strong>Afebrile and localized</strong>:<br></br>HZV<br></br>Contact dematitis
Malaria classic triad
Fever<br></br>Splenomegaly<br></br>TCP
Risk factors for TSS
Current menstruation (using tempones)<br></br>Postpartum/post abortion<br></br>Recent surgical procedure<br></br>Burns<br></br>Deep abscess<br></br><br></br><i>Sinusitis<br></br>IUD<br></br>Peritonsillar abscess<br></br>Nasal packing for epistaxis</i>
Commonly missed topics in Hx regarding infectious diseases
Immunocompromized<br></br>Age<br></br>Comorbidities<br></br>Travel Hx<br></br>ETOH<br></br>Substance abuse esp IVDU<br></br>Men sex with men<br></br>Endocarditis<br></br>Asplenia<br></br>Immunization status
Atypical causes of PUO
Meningitis<br></br>Endocarditis<br></br>TB<br></br>Malaria<br></br>HIV<br></br>Malignancy
DDx of Fever + ALOC (Hot and Altered)
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Features favoring encephalitis over meningitis
AMS<br></br>Focal signs<br></br>Altered behaviour and personality change<br></br>Speech changes<br></br>Seizures<br></br>CN palsies<br></br>Exaggerated DTRs
Meningitis Rx
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<div><b>Contraindications to lumbar puncture include:</b></div>
<div>1. Cellulitis over the proposed site of puncture, </div>
<div>2. Cardiopulmonary instability, </div>
<div>3. Bleeding diathesis, or platelet count below 50,000/μl, </div>
<div>4. Focal neurologic deficits, and </div>
<div>5. Signs of increased intracranial pressure, including papilledema</div>
<div><b>Pediatrics sepsis by age groups:</b></div>
<div>< 28 days</div>
<div>GBS, Listeria, E. Coli</div>
<div>1-3 months</div> <div>H.flu; pneumococcus, meningococcus, e coli</div> <div>3-36 months</div> <div>Same as above, less Hflu</div> <div>> 3 yr</div> <div>Same as above, but add in Group A Strep</div>
<div><b>CSF analysis is composed of:</b></div>
<div>1. Cell count and differential</div>
<div>2. Gram stain and Culture</div>
<div>3. Protein</div>
<div>4. Glucose</div>
<div>5. HSV PCR</div>
<div><b>What are risk factors for UTI in infants?</b></div>
<ul> <li>Age < 12 months</li> <li>Fever >24hours (boys) or >2 days (girls)</li> <li>Fever >39 degrees</li> <li>Absence of another source of infection</li> <li>Non-black race (boys) or white race (girls)</li> <li>Uncircumcised</li> </ul>
Dose of dexamethasone in meningitis
0.6 mg/kg/day in qid or<br></br>0.8 mg/kg/day in bid for 2-4 days
Who are the close contacts for meningitis?
Household contacts<br></br>HCW<br></br>Day care<br></br>Direct nose or mouth contamination (shared bottles,,,)
<p>Indications for primary closure of mammalian bite wounds</p>
<p>–Face or scalp</p>
<p>–Within 12 hours of injury (<24 hrs face)</p>
<p>–Simple wound, appropriate for single closure, no devitalized tissue</p>
<p>–Lack of underlying injury</p>
<p>–No systemic immunocompromising conditions</p>
<p>Indications for prophylactic antibiotics in bites</p>
<p>–Cat or human bite</p>
<p>–Livestock</p>
<p>–Monkey bites</p>
<p>–Deep puncture wounds</p>
<p>–Hand, foot, face, genital wounds</p>
<p>–Bites in immunosuppressed patients</p>
<p>–Wounds requiring surgical repair</p>
ABs for bites
Clavulin 875 mg bid x 3-5 days<br></br>in PCN allergy:<br></br>Doxy/septra/cipro/levo + flagyl/clinda<br></br>or<br></br>Moxifloxacin alone
<p>Tetanus prophylaxiss</p>
<ul> <li>Clean minor wounds</li> </ul>
<p>–< 3 or uncertain doses: Td</p>
<p>–Last dose within 5 years: None</p>
<p>–Last dose within 5 – 10 years: None</p>
<p>–Last dose > 10 years: Td</p>
<p></p>
<ul> <li>All other wounds (> 6 hours, > 1 cm deep, gross contamination, saliva/feces, ischemic, infected, avulsions, crush)</li> </ul>
<p>–< 3 or uncertain: Td, TIG</p>
<p>–Last dose within 5 years: None</p>
<p>–Last dose within 5 – 10 years: Td</p>
<p>–Last dose > 10 years: Td</p>
Rabies vaccine
0,3,7,14<br></br>Post exp proph Human Rabies Ig day 0:<br></br>20 IU/kg around the wound, the remainder given im distal to vaccination site<br></br><br></br>Captured animal==> examine the brain<br></br>Pet==> quarantine<br></br><br></br>Previously vaccinated pt==> vaccines only 0 and 3
Possible infection agents in fight fist inj
<ul> <li>Eikenella</li> <li>Strep viridans</li> <li>S. aureus</li> <li>Bacterioides</li> <li>Corynebacterium</li> </ul>
Pathogen for Lyme dis
Borrelia Burgdorferi<br></br>Vector= Ixodes deer tick (black legged tick)
Complications of Lyme dis
Neuropathy<br></br>Encephalitis<br></br>Migraines<br></br>Heart block<br></br>Arthritis<br></br>Myopericarditis<br></br>Ataxia
Pathognomonic features of Lyme dis
Erytema migrans<br></br>B/L facial palsy
<div>When indicated, what is the recommended prophylaxis for preventing Lyme disease in asymptomatic patients with a tick bite?</div>
A single 200 mg dose of doxycycline given within 72 hours of the deer tick bite
Rx of Lyme dis
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Complications of HSV & HZV inf
Pneumonia<br></br>Encephalitis/meningitios<br></br>Hepatitis<br></br>Severe sepsis<br></br>Death
<ul> <li>List five risk factors which increase your risk of severe HSV disease</li> </ul>
<ul> <li>Patients 12 years or over</li> <li>Those with chronic skin disease (ie. Atopic dermatitis)</li> <li>Those with underlying pulmonary disease</li> <li>Patients receiving salicylate therapy</li> <li>Those receiving oral or inhaled corticosteroids</li> <li>Patients who are immunocompromised</li><li>Neonates</li><li>Pregnant</li> </ul>
<p>Indications for VZIG</p>
<ul> <li>Exposed while Pregnant</li> <li>Exposed while Immunosuppressed</li> <li>Neonates born to women who have chicken pox 5 days prebirth to 2 days after delivery</li> <li></li> <li>Timing?</li> <li>Up to 96 hours of exposure (can be given up to 10 days later)</li> </ul>
Complications of HZV (shingles)
Postherpetic neuralgis (most common)<br></br>Ramsy Hunt Syndrome<br></br>HZ ophthamicus<br></br>Pneumonitis<br></br>Meningitis<br></br>Hepatitis<br></br>Encephalitis<br></br>Sepsis
<div><b><u>Ramsay Hunt (Herpes Zoster Oticus)</u></b></div>
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<p>In HIV patients, list 3 causes of neurologic symptoms</p>
“<ul> <li>Toxoplasmosis (multiple ring enhancing lesions)</li> <li>CNS lymphoma (solitary lesion)</li> <li>TB</li> <li>Progressive multifocal leukoencephalopathy</li> <li>Cryptococcus</li> <li>Bacterial abscess</li> <li>Benign brain tumours</li> <li>Malignant brain tumours</li> <li>Kaposi’s sarcoma</li> <li>Neurosyphilis</li> <li>HSV</li> <li>CMV</li> </ul>”
<p>List two other investigations to confirm a diagnosis of Toxoplasmosis</p>
<ul> <li>CD4 count (<100 highly suggestive)</li> <li>Toxoplasmosis IgG serology (positive, but negative does not exclude it)</li> <li>LP</li> </ul>
<p>What is the most common cause of pneumonia in HIV-infected patients?</p>
S. pneumoniae
<p>Pneumonia in HIV,List five investigations aside from basic bloodwork</p>
<ul> <li>ABG</li> <li>Sputum culture with Gram and acid fast staining</li> <li>Blood cultures for mycobacteria</li> <li>NAAT(nucleic acid amplification)/PCR for Mycobacterium</li> <li>CXR/CT</li> <li>Biopsy</li> </ul>
<p>What CD4 levels is prophylaxis started for:</p>
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<p>Aside from infections, what illnesses would make you suspicious for AIDs</p>
<ul> <li>HIV encephalopathy</li> <li>Kaposi’s sarcoma</li> <li>Burkitt’s lymphoma</li> <li>Brain lymphoma</li> <li>Progressive multifocal leukoencephalopathy</li> <li>Wasting syndrome due to HIV</li> </ul>
Mx of needlestick inj
Hands washing<br></br>PEP for HIV (triple therapy using Truvada+Dolutegravir)<br></br>LABS: creat, CBC, LFT<br></br>HIV titre at 3 months<br></br>Counsell to reduce transmission for 4 months (blood donation, unprotected sex, razors…)
Causes of TEN
Infections:<br></br> Mycoplasma pn<br></br> HSV<br></br> HIV<br></br>Drugs:<br></br> Anticonvulsants<br></br> ABs (septra, PCN, Cephalo)<br></br> NSAIDS<br></br> Allopurinol<br></br> Steroids<br></br>Auto immune:<br></br> SLE<br></br> HLA type (chinese/japanese)<br></br>Small pox vaccination
Cardiac complications of Kawasaki dis
<b>First 2 wks:</b><br></br>Myocarditis<br></br>Pericarditis<br></br>Peric.effusion<br></br>Vantr.dysfunction<br></br>Valv.dysfunction<br></br>Arrhythmias<br></br><br></br><b>2-4 wks:</b><br></br>Coronary a aneurysm
<p>Kawasaki Disease<br></br>Treatment</p>
<ul> <li>IV Ig 2 g/kg as single dose</li> </ul>
<p>–Expect rapid resolution of fever</p>
<p>–Decrease coronary artery aneurysms from 20% to < 5%</p>
<ul> <li>ASA - low dose vs high dose</li> </ul>
<p>–80-100 mg/kg/day until day 14</p>
<p>–3-5 mg/kg/day for 6 weeks</p>
<ul> <li>Repeat echocardiogram at 6 weeks</li> </ul>
DDx for fever and purpura
Meningococcemia<br></br>-Gonococcemia<br></br>-Bacterial Endocarditis<br></br>-Rocky Mountain Spotted fever<br></br>-TSS<br></br>-Q Fever<br></br>-Vasculitis<br></br>-DIC<br></br>-TTP<br></br>-HUS<br></br>-Leukemia
Rx of Meningitis
-Ceftriaxone 2g IV<br></br>-Vancomycin 1g IV OR 15 mg/kg IV<br></br>Metronidazole 500 mg IV (sinusitis is the likely source here)<br></br><br></br>Notes:<br></br>(given she has the meningococcemia rash, she is unlikely to benefit from dexamethasone administration as this is more effective with S. pneumonia)<br></br><br></br>(Acyclovir 10mg/kg would be appropriate to give this patient to cover for herpes encephalitis, but would NOT be accepted here as it is not, a “treatment for this condition”)
Clinical features of Infective Endocarditis
Janeway lesions<br></br>Osler nodes<br></br>Splinter hge<br></br>Petechiae<br></br>New murmur
Risk factors for IE?
Rheumatic heart dis<br></br>Cong heart dis<br></br>Immunocompromized<br></br>prosthetic valve<br></br>Prior Hx of IE
Causes of severe pharyngitis:
-Streptococcus pharyngitis (Group A, C, G)<br></br>-Viral infection (EBV, adenovirus, etc)<br></br>-Neisseria/Chlamydophila infection<br></br>-Mycoplasma pneumonia
“<span>What physical exam features would cause you to suspect a peritonsillar abscess?</span>”
-Fever<br></br>-Uvula deviation<br></br>-Trismus<br></br>-Unilateral swollen tonsil<br></br>-Free fluid collection on bedside ultrasound
Blood diarrhea differential diagnosis
-Salmonella<br></br>-Shigella<br></br>-Ecoli<br></br>-Campylobacter<br></br>-Yersinia<br></br>-Entomoeba<br></br>-Vibrio
“<span>What are indications for laboratory testing and stool testing in patients in whom you suspect foodborne illness?</span>”
-Signs of hypovolemia<br></br>-Bloody diarrhea<br></br>-Fever<br></br>-Severe pain<br></br>-Recent antibiotic use<br></br>-Elderly<br></br>-Immunocompromised<br></br>-Symptoms >1 week<br></br>-Signs of sepsis
“DDX:<br></br><img></img>”
-guttate psoriasis<br></br>-syphilis<br></br>-tinea versicolor<br></br>-contact dermatitis<br></br>-seborrheic dermatitis<br></br>-lichen planus<br></br>-scabies<br></br>-eczema
Diagnostic Criteria for TSS
<ol> <li>Fever (Temp > 38.8)</li> <li>Rash – diffuse macular erythroderma</li> <li>Desquamation (1 – 2 weeks after onset of illness) - Particularly of the palm and soles</li> <li>Hypotension: Systolic BP <90 for adults and <5th percentile for age in <16</li> <li>Multisystem involvement (3 or more): <ul> <li><em>GI, muscular (CK >2x upper limit), </em></li> <li><em>mucous memberane (vaginal, oral, conjuctival) hyperemia, </em></li> <li><em>renal (>2x Creat), hepatic )>2x LFT rise), </em></li> <li><em>hematologic (plt < 100,000), </em></li> <li><em>CNS (disorientation and no focal)</em></li> </ul> </li> <li>Negative Blood, throat, or CSF cultures (other than Staph aureus in Blood) and Negative Serology for RMSF or Measles</li> </ol>
<p>What are the suggestions for obtaining a Head CT prior to LP?</p>
ALOC<br></br>Focal symptoms/signs<br></br>Seizure<br></br>Papilledema<br></br>Immuncompromised<br></br>Hx of malignancy<br></br>Hx suspicious of CNS dis (CVA, SOL)<br></br>Age > 60
Differentiation between pemphigus vulgaris and bullous pemphigoid
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<p>List four infectious causes and three potential drug causes for Erythema Nodosum</p>
<ol> <li>Infection: <ol> <li>Bacterial: <ul> <li>Streptococcal</li> <li>TB</li> <li>Leprosy</li> <li>Mycoplasma pneumoniae</li> </ul> </li> <li>Fungal: <ul> <li>Coccidomycosis</li> <li>histoplasmosis</li> <li>Blastomycosis</li> </ul> </li> <li>Viral: <ul> <li>IMN</li> <li>Cat scratch dis</li> <li>HBV</li> </ul> </li> </ol> </li> <li>Drugs: <ol> <li>Sulfonamides</li> <li>OCP</li> <li>PCN</li> </ol> </li> <li>Ulcerative disease of GIT (UC)</li> <li>Malignancy</li> <li>Idiopathic</li> </ol>
Causes of contact dermatitis<br></br>
Poison ivy<br></br>Nickel<br></br>Neomycin<br></br>Bacitracin<br></br>Perfumes<br></br>Sodium gold thiosulfate<br></br>Formaldehyde
Allergic vs non-allergic angioedema
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Risk factors for erysipelas and cellulitis
Immunocompromized pt<br></br>PVD<br></br>Lymphedema<br></br>Skin breakdown<br></br>Venous insufficiency<br></br>Obesity<br></br>?DM
DDx of abd pain out of proportion
Necrotizing faciitis<br></br>Ischemia<br></br>Torsion<br></br>Malingering
“Fifths disease/ erythema infectiosum<br></br><span>What patients are at risk of developing complications from this condition?</span>”
Pregnant patients (the fetus can develop hydrops fetalis)<br></br>Immunocompromised patients<br></br>Patients with iron deficiency anemia, HIV, sickle cell disease, spherocytosis, thalassemia<br></br><i>Due to risk of aplastic crisis: Parvo b19 can stop erythrocyte production</i>
“<span>What other historical red flags for headache must be considered</span>”
-Sudden onset or worst at onset<br></br>-Positional headache<br></br>-Fever, immunocompromised<br></br>-Dizziness, focal weakness or other neurological complaints<br></br>-Clotting disorder/ anticoagulation<br></br>-Trauma<br></br>-Neck, facial pain, cervical manipulation<br></br>-Eye pain/ vision change<br></br>-Jaw claudication, muscle aches, temporal artery pain<br></br>-Multiple patients with headache
<p>Rabies: most concerning animals, incubation period, how you can get it, mortality, S/Sx</p>
<ul> <li>Most concerning animals:</li> </ul>
<p><em>Bats, raccoons, foxes, skunks, unknown/wild dogs</em></p>
<ol> <li>Incubation period: 5 d – 1 yr (avg 20 -90 days)</li> <li>Risk: 5 – 80%</li> <li>You can get it with a bite, scratch, lick over an open wound or mucus membrane or exposure to brain tissue or CSF</li> <li>Mortality: once symptoms develop it is considered to be 100% fatal</li> <li>S/Sx:</li> </ol>
<p><em>Prodrome: Pain/parasthesias at site of bite/scratch, fever, h/a, anorexia</em></p>
<p><em>Neurologic stage (2 – 7d) Aphasia, incoordination, Increased lacrimation, increased salivation, paresis, paralysis, MS changes, hyperactivity</em></p>
<p><em>Late symptoms: decreased BP, coma, DIC, arrhythmia, cardiac arrest, DEATH</em></p>
<p>Outline the PEP for Rabies & the immunization schedule</p>
” <p><strong>Animal Type</strong></p> <p><strong>Evaluation & Disposition of Animal</strong></p> <p><strong>Recommendation for Prophylaxis</strong></p> <p>Dogs, Cats, Ferrets</p> <p>Healthy & avail for 10 days obs</p> <p>Don’t start unless animal develops symptoms then immediately HRIG + HDCV</p> <p>Rabid or Suspected Rabid</p> <p>Immediate HRIG + HDCV</p> <p>Unknown</p> <p>Contact local PH</p> <p>Skunks, Raccoons, Bats, Foxes, Coyotes & most carnivores</p> <p>Regard as Rabid</p> <p>Immediate HRIG + HDCV</p> <p>Livestock, rodents, rabbits (incl hares, squirrels, guinea pigs, hamsters, gerbils, chipmunks, rats, mice, woodchuks</p> <p>Almost never require anti-rabies</p> <p>HRIG (Human Rabies IG) 20U/kg infiltrate as much as poss around the wound and then the rest IM in the gluteal area</p> <p>HDCV (Human Diploid cell vaccine) 1.0mL IM (deltoid) on days 0, 3, 7, 14 & 28</p> <p>If previous vaccination then HDCV on 1.0mL IM on days 0 & 3</p> “
HIV with HA and fever
Toxoplasmosis<br></br>Histoplasmosis<br></br>Primary CNS lymphoma<br></br>Cryptococcus Neoforms (CD4<100)
Complications of malaria
Anemia<br></br>Cerebral malaria (encephalitis, seizure, edema)<br></br>GN<br></br>Splenic rupture<br></br>Hypoglycemia
What are the objective of treating strept pharyngitis<br></br>
To prevent the following: <br></br>Rheumatic fever<br></br>Peritonsillar/retropharyngeal abscess<br></br>Suppurative lymphadenitis<br></br><br></br>Also to hasten recovery
What are the complications of TEN
Sepsis<br></br>Electrolytes disturbances <br></br>Pulm edema<br></br>ARDS<br></br>Renal failure <br></br>Death
“John’s Criteria for Rheumatic fever”
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<div>What other treatment can you add for severe refractory cases of toxic shock syndrome?</div>
Intravenous immunoglobulin
<div><b><u>Rocky Mountain spotted fever (RMSF)</u></b></div>
<div>· Patient with a history of recently being in the woods hiking or camping</div>
<div>· Complaining of<b>abrupt onset of severe headache</b>,<b>photophobia</b>,<b>vomiting</b>,<b>diarrhea</b>,<b>and myalgia</b></div>
<div>· PE will show<b>maculopapular eruption on the palms and soles</b></div>
<div>· Diagnosis is made by skin biopsy</div>
<div>· Most commonly caused by<b><i>Rickettsia rickettsia</i></b></div>
<div>· Treatment is<b>ALWAYS doxycycline</b>,<b>even in children</b></div>
What ocular findings may be seen in RMSF?
Nonexudative conjunctivitis and periorbital edema
<b><u>Rocky Mountain spotted fever</u></b>
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Rabies
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<div><b><u>Roseola (Exanthem Subitum)</u></b></div>
“<div>Patient will be a child 6 months - 3 years of age</div> <div>With a history of high fever lasting 3 - 4 days</div> <div>Complaining of a<b>rash that started</b><b><span>after</span></b><b>the fever went away</b></div> <div>PE will show blanching macular or maculopapular rash with a distribution that begins at the<b>neck and trunk region and spreads to the face and extremities<br></br></b><img></img><b><br></br></b></div>”
Hand Foot Mouth dis
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Mumps
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Measles
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Rubella
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Famous Rashes in childhood
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IMN
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Other than IMN, what conditions can EBV cause?
<div>B-cell lymphoma, </div>
<div>Hodgkin disease,<br></br>Burkitt lymphoma, and</div>
Nasopharyngeal carcinoma<br></br>EBV can affect nearly all organ systems. Neurologic complications such as encephalitis, meningitis, and<strong>Guillain-Barré</strong><br></br>
Risk factors for contracting HIV after needle stick inj
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Fifth Dis
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