3 Flashcards
What is the presentation of glucose–6–phosphate dehydrogenase deficiency?,
Sudden, severe, intravascular hemolysis; jaundice, dark urine, weakness, and tachycardia.
How is glucose–6–phosphate dehydrogenase deficiency diagnosed?,
High LDH, bilirubin, and reticulocyte count with a normal MCV and hemoglobinuria. Heinz bodies are inclusions in red cells. Definitive test is the G6PD level.
What is the treatment for glucose–6–phosphate dehydrogenase deficiency?,
Hydration and transfusion. Avoid oxidant stress.
What is aplastic anemia?,
Failure of bone marrow, resulting in anemia, leukopenia, and thrombocytopenia (pancytopenia). The marrow is empty.
What are the causes of aplastic anemia?,
Radiation, benzene, NSAIDs, chloramphenicol, alcohol, chemotherapeutics. Tb, lymphoma. Hepatitis, HIV, CMV, EBV, Parvovirus B19. The most common etiology is idiopathic.
What is the presentation of aplastic anemia?,
Bleeding from thrombocytopenia. Fatigue from anemia and infections from neutropenia. Pancytopenia on CBC. Marrow biopsy confirms.
What is the treatment for aplastic anemia?,
Bone marrow transplantation or immunosuppressive agents.
What is acute leukemia?,
Derangement of pluripotent stem cell, resulting in the destruction of marrow. Leukemic blasts crowd out marrow cells, resulting in pancytopenia. Blood cells lose the ability to mature and function.
What are the causes of acute leukemia?,
Most cases are idiopathic; radiation exposure, benzene, melphalan and etoposide, retroviruses.
What is the presentation of acute leukemia?,
Fatigue from anemia. Bleeding from thrombocytopenia. Infection from the underproduction of white blood cells.
Which type of anemia is more common in children?,
Acute lymphocytic leukemia (ALL) is more common in children. Acute myelogenous leukemia (AML) is more common in adults. Enlargement of the liver, spleen, and lymph nodes and bone pain are common at presentation.
How is acute leukemia diagnosed?,
WBC can be low, normal, or elevated. Thrombocytopenia, anemia; leukemic blasts in peripheral blood. Marrow biopsy >20% blasts confirms.
What are the markers of acute myelogenous leukemia?,
AML is characterized by Auer rods, myeloperoxidase, and esterase.
What are the markers of acute lymphocytic leukemia?,
ALL is characterized by common ALL antigen and terminal deoxynucleotidyl transferase (TdT).
What is chronic myelogenous leukemia (CML)?,
Massive overproduction of myeloid cells. Philadelphia chromosome is characteristic, producing tyrosine kinase.
What is the presentation of chronic myelogenous leukemia?,
Markedly elevated white blood cell count fatigue, night sweats, and low–grade fever. Abdominal pain from massive enlargement of the spleen. Bone pain.
How is chronic myelogenous leukemia diagnosed?,
Elevated WBC consisting of neutrophils. Leukocyte alkaline phosphatase score is diminished. Basophilia characteristic of CML and all myeloproliferative disorders such as polycythemia vera. Platelets elevated.
What is the treatment for chronic myelogenous leukemia?,
Imatinib which is direct inhibitor of the tyrosine kinase produced by the Philadelphia chromosome. 90% hematologic response.
What is chronic lymphocytic leukemia?,
Massive overproduction of mature; lymphocytes from production of B lymphocytes.
What is the presentation of chronic lymphocytic leukemia?,
CLL can often present as an asymptomatic elevation of white cells. 90% being over the age of 50. Fatigue, lethargy, and enlargement of lymph nodes. Infiltration of spleen, liver, and bone marrow.
How is chronic lymphocytic leukemia diagnosed?,
Older patient with a marked elevation in the white cell count with a marked lymphocytic predominance. The marrow is infiltrated with the leukemic lymphocytes with CD19 antigen.
What is multiple myeloma?,
Plasma cell overproduction, replacing the bone marrow; large quantities of functionless immunoglobulins.
What is the presentation of multiple myeloma?,
Bone pain. Pain in back, ribs; fractures. Radiculopathy. Encapsulated organisms (Pneumococcus, Haemophilus). Renal failure, anemia. Hypercalcemia: polyuria, polydipsia, altered mental. Weakness, pallor.
How is multiple myeloma diagnosed?,
Normochromic, normocytic anemia. Protein electrophoresis monoclonal immunoglobulin spike. Skull punched out lesions. beta2 microglobulin. Hypercalcemia from bone destruction. Elevated BUN, creatinine from kidney damage. Biopsy: 10% plasma cells.
What is Bence–Jones protein?,
Urinary Bence–Jones protein is nonfunctional gamma globulin found in multiple myeloma. It will not react with urine dipstick test.
What is the treatment for multiple myeloma?,
Bone marrow transplantation. Older patients should receive melphalan and prednisone.
What is monoclonal gammopathy of uncertain significance?,
Overproduction of immunoglobulin by plasma cells without manifestations MGUS is present in 1% > 50 and in 3% of those > age 70. Monoclonal immunoglobulin spike on electrophoresis. Treatment is not necessary.
What is Hodgkin disease?,
A neoplastic transformation of lymphocytes in the lymph node with Reed–Sternberg cells; spread to contagious areas of lymph nodes. Bimodal age peaks in the 20s and 60s.
What is the presentation of Hodgkin disease?,
Enlarged, rubbery, nonerythematous, nontender lymph nodes. symptoms are night sweats, weight loss, fevers. Pruritus; cervical, supraclavicular, axillary lymphadenopathy most common. Spleen, skin, gastric, lung, CNS.
What is the treatment for Hodgkin disease?,
Localized disease is managed with radiation. All patients with symptoms and stage III or stage IV disease are managed with chemotherapy.
What is non–Hodgkin lymphoma?,
Neoplastic transformation of B and T lymphatic cells. Accumulation of neoplastic cells in both the lymph nodes and diffusely in extra–lymphatic organs and the bloodstream. Reed–Sternberg cell is absent.
What conditions predispose to non–Hodgkin lymphoma?,
Infections such as HIV, hepatitis C, Epstein–Barr, HTLV–I, and Helicobacter pylori predispose to the development of NHL.
What is the presentation of non–Hodgkin lymphoma?,
Enlarged, rubbery, nonerythematous, nontender lymph nodes. symptoms are night sweats, weight loss, fevers. Pruritus may occur.
What sites are affected by non–Hodgkin lymphoma?,
NHL is the same as HD except that HD is localized to cervical and supraclavicular nodes. NHL involves extra–lymphatic sites and blood. CNS is more common NHL. HIV patients often have CNS NHL.
What is the treatment for non–Hodgkin lymphoma?,
Local disease is treated with radiation, and those with symptoms or Stages III and IV receive combination chemotherapy.
A 21–year–old woman with epistaxis and heavy periods. She has a PT of 12 seconds, a PTT of 40 seconds (prolonged), and 200,000/mm3 platelets. What is the diagnosis?,
Idiopathic thrombocytopenic purpura. Also known as primary immune thrombocytopenic purpura.
What is idiopathic thrombocytopenic purpura?,
Thrombocytopenia caused by idiopathic production of an antibody to platelets; often associated with lymphoma, chronic lymphocytic leukemia, HIV, and connective tissue diseases.
What is the presentation of idiopathic thrombocytopenic purpura?,
Bleeding skin, nasal, oral, GI, urine, vagina. Young, female; epistaxis, bruising, hematuria, uterine and GI bleeding. Petechiae, purpura, ecchymoses. Splenomegaly absent.
How is idiopathic thrombocytopenic purpura diagnosed?,
Thrombocytopenia. Antiplatelet Ab have a high sensitivity, poor specificity. Marrow filled with megakaryocytes, indicating platelet destruction. Smear and creatinine are normal, excluding HUS, TTP, DIC.
What is the treatment for idiopathic thrombocytopenic purpura?,
Prednisone. Splenectomy if very low platelet counts.
What is Von Willebrand disease?,
Platelet–type bleeding, autosomal dominant, decreased von Willebrand factor; VWD is the most common congenital disorder of hemostasis. Decreased ability of platelets to adhere to endothelial lining of blood vessels.
What is the presentation of Von Willebrand disease?,
Epistaxis, petechiae, bruising, and menstrual abnormalities; gastrointestinal and urinary tract bleeding.
How is Von Willebrand disease diagnosed?,
Platelet count is normal. The bleeding time is increased. Von Willebrand factor is low. Ristocetin platelet aggregation test is abnormal. PTT may be elevated.
What is the treatment for von Willebrand disease?,
Desmopressin acetate (DDAVP) for mild bleeding. Factor VIII replacement is used if desmopressin is not effective and the bleeding continues. Aspirin contraindicated. FFP is not useful.
Which coagulopathies cause a prolonged prothrombin time?,
Factor VII deficiency, vitamin K deficiency, liver disease, warfarin use, factor VII inhibitor.
Which coagulopathies cause a prolonged PTT?,
vWF and factors VIII, IX, XI, or XII deficiencies; heparin, antiphospholipid antibody
Which coagulopathies cause a prolonged PT and PTT?,
Prothrombin, fibrinogen, factor V, factor X or combined factor deficiencies, liver disease, DIC, supratherapeutic heparin or warfarin; combined heparin and warfarin.
What is hemophilia?,
Deficiency of clotting factor 8 in hemophilia A and deficiency of factor 9 in hemophilia B resulting in increased bleeding. X–linked recessive, resulting in disease in males. Females are carriers. Hemophilia A is far more common than B.
Why does hemophilia not express in females?,
Females do not express the disease because homozygosity results in intrauterine death of the fetus.
What is the presentation of hemophilia?,
Mild deficiencies result in absence of symptoms or with symptoms only during surgery or trauma. Severe deficiency results in spontaneous bleeding. Factor–type bleeding is deeper than bleeding caused by platelets.
What type of bleeding is associated with factor deficiency?,
Factor deficiencies cause hemarthrosis, hematoma, gastrointestinal bleeding, urinary bleeding, bruising, CNS bleeding. Severe hemophilia presents by age two or circumcision.
How is hemophilia diagnosed?,
A prolonged PTT with a normal PT. Specific factor VIII or IX levels allow for a precise diagnosis of hemophilia A or B.
What is the treatment of hemophilia?,
Mild hemophilia can be treated with desmopressin (DDAVP). Severe deficiencies are treated with replacement of the specific factor. Desmopressin is ineffective for hemophilia B.
What factor deficiency results from vitamin K deficiency?,
The deficiency of vitamin K results in decreased production of factors 2, 7, 9, and 10. Caused by dietary deficiency, malabsorption, and antibiotics that kill the colon bacteria that produce vitamin K.
What is the presentation of vitamin K deficiency?,
Bleeding may occur at any site. Oozing at venipuncture sites.
How is vitamin K deficiency diagnosed?,
PT and PTT are elevated. A correction of PT and PTT in response to giving vitamin K is the most common method of confirming the diagnosis.
What is the treatment for vitamin K deficiency?,
Severe bleeding is treated with fresh frozen plasma. Vitamin K is given at the same time.
Why do patients with liver disease have increased PT and PTT?,
Coagulopathy is caused by decreased production of clotting factors by the liver. Any severe liver disease or cirrhosis can cause decreased production of clotting factors.
What are the effects of coagulopathy of liver disease?,
Bleeding at any site, gastrointestinal tract is the most common site. Vitamin K does not result in improvement. Low platelet counts are often caused by hypersplenism that accompanies the liver disease.
What is the treatment of coagulopathy of liver disease?,
Fresh frozen plasma severe bleeding.
What is disseminated intravascular coagulation?,
Consumptive coagulopathy from major illness, resulting in consumption of platelets and clotting factors; bleeding with a microangiopathic hemolysis and fibrin products; occasionally thrombosis.
What are the causes of disseminated intravascular coagulation?,
Sepsis is most common. Any cell destruction and release of tissue factor. Rhabdomyolysis, adenocarcinomas, heatstroke, transfusion reactions, burns, head trauma, abruption, amniotic embolism, trauma, pancreatitis, snakebites, leukemia.
What is the presentation of disseminated intravascular coagulation?,
Bleeding from any site. Thrombosis is less common. Hemolysis often may lead to acute renal failure, jaundice, confusion.
How is disseminated intravascular coagulation diagnosed?,
Serious underlying disorder with bleeding, elevation PT, PTT; decrease platelets. Fibrinogen low. D–dimers and fibrin– split products are increased. Schistocytes with intravascular hemolysis.
What is the treatment for disseminated intravascular coagulation?,
Fresh frozen plasma and platelet transfusions. Heparin is rarely used except in thrombosis.
What are the names of the semisynthetic penicillinase–resistant penicillins?,
Oxacillin, cloxacillin, dicloxacillin, methicillin, nafcillin
Which bacteria are susceptible to the semisynthetic penicillins?,
Staphylococci and streptococci. Oxacillin, nafcillin, dicloxacillin, cloxacillin. Exclusively effective against Gram–pos cocci, particular staph. Methicillin not used because interstitial nephritis.
What are the indications for the semisynthetic penicillins?,
Used when Staphylococcus is sensitive to the semisynthetic penicillins and if concurrent Gram–negative infection is not suspected. More efficacious than vancomycin when the organism is sensitive.
What antibiotic is used to treat resistant–resistant Staph aureus?,
MRSA is treated primarily with vancomycin. Oral linezolid or IV quinupristin–dalfopristin are alternatives for MRSA.
What is the coverage of linezolid?,
Drug–resistant enterococcus, staphylococcus, and pneumococcus.
Which bacteria are sensitive to penicillin G, penicillin VK, ampicillin, and amoxicillin?,
Effective against streptococci, such as S. pyogenes, viridans group streptococci, and S. pneumonia, but not against staphylococci.
When can ampicillin and amoxicillin be used against staphylococcal infections?,
Ampicillin and amoxicillin are only effective against staph when ampicillin is combined with the beta–lactamase inhibitor sulbactam or when amoxicillin is combined with clavulanate.
What is the coverage of ampicillin against E coli?,
Ampicillin also has some activity against E. coli. Ampicillin and amoxicillin are effective against enterococci and Listeria. Useful against Gram–negative bacteria, such as Neisseria.
What are the first–generation cephalosporins?,
Cefazolin, cefadroxil, cephalexin.
What are the second–generation cephalosporins?,
Cefoxitin, cefotetan, cefuroxime, cefprozil, loracarbef.
What is the coverage of the first–generation cephalosporins?,
Same organisms that the semisynthetic penicillins will cover. In addition to staphylococci and streptococci, 1st and 2nd gen cephalosporins will also cover some Gram–neg. 1st gen agents will only reliably cover Gram–neg Moraxella and E. coli.
What is the coverage of second–generation cephalosporins?,
Cover everything a first–generation cephalosporin covers, as well as a few more Gram–negative bacilli such as Providencia, Haemophilus, Klebsiella, Citrobacter, Morganella, and Proteus.
What is the coverage of the third–generation cephalosporins?,
3rd gen, particularly ceftazidime, are not reliable against staphylococcus. 4th gen cephalosporin, cefepime, will cover staph and strep, but should not be used for exclusively Gram–pos infections.
What is the allergic cross–reactivity of penicillins with cephalosporins?,
For persons allergic to penicillin, there is only 5% risk of cross–reaction with cephalosporins. When the allergic reaction was a rash, a cephalosporin can be used. When the reaction was anaphylaxis, a cephalosporin should not be used.
What antibiotic should be used in patients with a history of an anaphylactic reaction to a penicillin?,
A macrolide (clarithromycin or azithromycin) or levofloxacin, gatifloxacin, or moxifloxacin can be used. For serious infections, use vancomycin, linezolid, or daptomycin.
What are the indications for macrolides (erythromycin, clarithromycin, azithromycin), extended fluoroquinolones (levofloxacin, gatifloxacin, moxifloxacin), and clindamycin?,
Alternatives to penicillin and cephalosporins for Gram–pos infection. Macrolides should not be used for serious staph. Extended quinolones very good for strep, particularly S pneumoniae in absence of penicillin resistance. Good against staph; not MRSA.
Why should ciprofloxacin not be used to treat pneumonia?,
Ciprofloxacin does not cover Strep pneumoniae.
What are the indications for vancomycin, linezolid, quinupristin, dalfopristin?,
Alternatives for Gram–pos infections when penicillin allergy or MRSA. Linezolid is the only oral MRSA.
What is the coverage of linezolid, quinupristin, dalfopristin?,
Linezolid, quinupristin, dalfopristin are effective against MRSA and vancomycin–resistant enterococci.
What is the activity of antipseudomonal penicillins (piperacillin, ticarcillin, mezlocillin) against Gram–negative bacilli?,
Fully active against range of Gram–negative bacilli, such as the Enterobacteriaceae including Pseudomonas. Enterobacteriaceae include E. coli, Proteus, Enterobacter, Citrobacter, Morganella, Serratia, Klebsiella.
What is the activity of ticarcillin and mezlocillin against MSSA?,
Antipseudomonal penicillins are only active against staph when combined with a beta–lactamase inhibitor, such as piperacillin/tazobactam or ticarcillin/clavulanate. Not MRSA.
What is the coverage of ampicillin/sulbactam and amoxicillin/clavulanate?,
Cover strep and staph and Gram–neg bacilli, but not Pseudomonas. All penicillins will cover sensitive streptococci.
What are the third–generation cephalosporins?,
Ceftazidime, cefotaxime, ceftriaxone, cefotaxime.
What is the fourth generation cephalosporin?,
Cefepime
What is the coverage of third– and fourth–generation cephalosporins?,
Fully active against full range of Gram–neg bacilli, such as the Enterobacteriaceae. Only ceftazidime and cefepime will cover Pseudomonas. Cefepime also covers staph.
What is the Gram–negative coverage of second–generation agents?,
Cover some of the Enterobacteriaceae, but not Pseudomonas.
What is the coverage of the third generation cephalosporins?,
Predominantly for use against Gram–negative organisms. Ceftriaxone and cefotaxime cover best for penicillin–insensitive pneumococci which cause meningitis or pneumonia.
What is the coverage of quinolones (ciprofloxacin, levofloxacin, gatifloxacin, moxifloxacin, ofloxacin)?,
Cover most Enterobacteriaceae, such as E. coli, Proteus, Enterobacter, Haemophilus, Moraxella, Citrobacter, Morganella, Serratia, and Klebsiella. Only ciprofloxacin will cover Pseudomonas.
What is the coverage of extended–spectrum quinolones?,
Moxifloxacin, levofloxacin, gatifloxacin are also active against Gram–positive cocci, in particular Strep pneumoniae. Good for pneumonia because also cover Mycoplasma, Chlamydia, Legionella.
What is the coverage of aminoglycosides (gentamicin, tobramycin, amikacin)?,
Gram–negative coverage. Aminoglycosides are synergistic with ampicillin in treatment of staph.
What is the coverage of monobactams?,
Aztreonam is exclusively a Gram–negative agent, with no strep or staph coverage.
What is the coverage of carbapenems (imipenem, meropenem, ertapenem)?,
Enterobacteriaceae and Pseudomonas with Gram–neg coverage. Excellent staph and anaerobic coverage. Used in Gram–negative infections, but also effective polymicrobial. Ertapenem not cover Pseudomonas.
What agent is most active against intraabdominal anaerobes?,
Metronidazole. Clindamycin is less active against intraabdominal anaerobes. Metronidazole has good anaerobic Gram– neg in bowel, such as B fragilis. Metronidazole is first–line against C difficile.
What is the coverage of clindamycin?,
Clindamycin may have some advantages over metronidazole against the anaerobic streptococci found in the mouth.
What agents have intraabdominal anaerobic coverage?,
Metronidazole, carbapenems and beta–lactam/beta–lactamase combinations (piperacillin/tazobactam, ticarcillin/clavulanate, ampicillin/sulbactam, or amoxicillin/clavulanate). 2nd gen cephalosporins cefoxitin and cefotetan, have fair activity against.
A 15–year–old male with fever, headache, nausea, and vomiting. Neck stiffness and photophobia. What is the next step?,
Lumbar puncture.
What is the most common cause of meningitis after the neonatal period?,
Streptococcus pneumoniae is the most common cause of meningitis for all patients beyond the neonatal period. Neisseria meningitidis is the most common cause of meningitis in adolescents.
What factors predispose to listeria monocytogenes meningitis?,
Listeria monocytogenes is more common with immune system defects, HIV, steroid use, leukemia, lymphoma, and various chemotherapeutic agents. Neonates and the elderly.
What is the most common cause of meningitis in the elderly and infants?,
Streptococcus pneumoniae is the most common etiology. Listeria is more common in the very old and infants.
Which patients are at risk for staphylococcal meningitis?,
Staphylococcus aureus is more common in those who have had any form of neurosurgery.
Which patients are at risk for cryptococcus meningitis?,
Cryptococcus is more common in those who are HIV positive and who have profound decreases in their T–cell counts to levels less than 100 cells/mm3.
Which persons are at risk for Rocky Mountain spotted fever meningitis?,
Rocky Mountain spotted fever is common in those who have been exposed to ticks in the mid–Atlantic areas, such as the Carolinas, Kentucky, Tennessee, Delaware, Maryland, Virginia, Georgia, Florida, Oklahoma, etc.
What area is associated with Lyme meningitis?,
Lyme disease can also cause meningitis and is more common in the Northeast. Tuberculosis and syphilis are also associated with meningitis.
What are the CSF characteristics in aseptic meningitis?,
CSF has lymphocytic pleocytosis and bacterial cultures are negative.
What are the causes of aseptic meningitis?,
Enteroviruses, arboviruses (St. Louis encephalitis virus, West Nile virus), HIV, herpes simplex, and lymphocytic choriomeningitis virus.
What is the most common cause of neonatal meningitis?,
Group B Streptococcus (Streptococcus agalactiae) is the most common cause of meningitis in the neonatal period.
What is the clinical presentation of meningitis?,
Fever, photophobia, headache, nuchal rigidity (Kernig, Brudzinski), nausea, vomiting, seizures. The most common deficit from meningitis is damage to 8th cranial nerve (hearing).
What type of meningitis is associated with a petechial rash?,
Neisseria. A rash on the wrists and ankles with centripetal spread toward the body suggests Rocky Mountain spotted fever.
What type of meningitis is associated with facial palsy?,
Facial nerve palsy is suggestive of Lyme disease. Pulmonary symptoms or an abnormal chest x–ray suggest tuberculosis.
When should a CT scan be done before lumbar puncture in patients with suspected meningitis?,
CT should be done before lumbar puncture if papilledema, focal motor deficits, new onset seizures, mental status abnormalities, or immunocompromise (HIV, immunosuppressive).
What should be done if the lumbar puncture is delayed more than 20–30 minutes?,
An empiric dose of antibiotics should be given.
What are the CSF findings in bacterial meningitis?,
Protein elevated with bacterial meningitis. Opening pressure elevated. Gram stain has a limited sensitivity; positive 50%. The most useful test is the cell count. Only bacterial meningitis causes thousands of cells, all neutrophils.
What types of meningitis are associated with an elevation in lymphocytes?,
Viral infection, Rickettsia, Lyme disease, tuberculosis, syphilis, or fungal (cryptococcal) etiology. Normal CSF cell count is
What is the empiric treatment of bacterial meningitis in adults?,
Vancomycin (pneumococci are resistant penicillin) plus a 3rd gen cephalosporin, such as ceftriaxone. Ampicillin is added to cover Listeria if immune defects, >50, or
What is the treatment of Lyme meningitis?,
Lyme disease is treated with ceftriaxone.
What is the treatment of Cryptococcal meningitis?,
Cryptococcus is treated with amphotericin. Followed by fluconazole in HIV–positive patients for life or until the patient is on HAART and is asymptomatic with a CD4 count >100.
What is the treatment of neurosyphilis?,
Neurosyphilis is treated with high–dose intravenous penicillin.
What is the treatment of tuberculosis meningitis?,
TB meningitis is treated the same as pulmonary tuberculosis (though a longer duration of 9–12 months).
What are the indications for corticosteroid in meningitis?,
Steroid use in adult meningitis is appropriate for TB meningitis and bacterial meningitis.
What are the recommendations for adjunctive dexamethasone for bacterial meningitis?,
Reduces inflammatory response to bacterial lysis; given with antibiotics for 4 days if bacterial meningitis is confirmed by positive Gram stain or >1000 WBCs in CSF.
What is encephalitis?,
Infection of brain parenchyma usually caused by any viruses. The most common cause is HSV type 1. Varicella–zoster virus, CMV, enteroviruses, Eastern and Western equine encephalitis, St. Louis, and West Nile.
What is the presentation of encephalitis?,
Altered mental status with fever and headache. Confusion to lethargy or coma. Focal deficits. Neck stiffness. Seizures.
How is HSV encephalitis diagnosed?,
Lumbar puncture PCR has eliminated the need for biopsy. PCR for HSV has a 98% sensitivity and >95% specificity. HSV has a predilection for temporal lobes.
What is the treatment for HSV encephalitis?,
Intravenous acyclovir.
What is the treatment of cytomegalovirus encephalitis?,
Ganciclovir or foscarnet are active against CMV.
An HIV–negative man with a seizure. Aphasia and weakness of the right hand and leg. A CT scan of the head with contrast shows a ring enhancing lesion. What is the diagnosis?,
Brain abscess.
What are the causes of brain abscesses?,
Bacteria can spread into the brain from otitis media, sinusitis, mastoiditis, or dental infections. Organisms may also spread through the bloodstream from endocarditis or pneumonia.
Which organisms cause brain abscesses?,
Brain abscesses most commonly Streptococcus 60–70%, Bacteroides 20–40%, Enterobacteriaceae 25–35% and Staph 10%, often polymicrobial. Toxoplasmosis can reactivate in HIV when CD4
What is the presentation of brain abscess?,
Headache. Fever, focal neurologic deficits, seizures.
How is brain abscess diagnosed?,
Brain abscess and malignancy enhance with contrast. MRI more accurate than CT. Stereotactic aspiration for Gram stain, culture. In HIV, 90% of brain lesions will be toxoplasmosis or lymphoma.
What is the treatment for brain abscess?,
Surgical drainage. Penicillin, metronidazole, and a third–generation cephalosporin, such as ceftazidime. HIV patients are treated empirically with pyrimethamine and sulfadiazine.
What are the causes of otitis media?,
The most common organisms are Strep pneumoniae (35–40%), H. influenzae (nontypeable; 25–30%), and Moraxella catarrhalis (15–20%). Viruses.
What is the presentation of otitis media?,
Ear pain, fever, and decreased hearing. Immobility of the membrane on insufflation.
What is the treatment for otitis media?,
High–dose amoxicillin. Amoxicillin–clavulanate is used if recent amoxicillin or if no response to amoxicillin. Alternatives: Cefuroxime, loracarbef, cefprozil, or cefdinir or cefixime.
What is the treatment for otitis media in severe allergy to penicillin?,
Macrolides, such as azithromycin or clarithromycin. Levofloxacin, moxifloxacin or gatifloxacin are acceptable. TMP/SMZ is poorly active against Streptococcus pneumoniae.
What is the most common site of sinusitis?,
The most common site of infection is the maxillary sinus.
What are the cause of sinusitis?,
Viruses are responsible for most cases. Bacterial organisms are strep pneumonia, H influenza (non–typable), Moraxella catarrhalis.
What is the presentation of sinusitis?,
Facial pain, headache, postnasal drainage, and purulent nasal drainage. Headache, fever, tooth pain.
How is sinusitis diagnosed?,
If imaging is required because of concern of complications, a CT scan is the best test.
What is the treatment for sinusitis?,
High–dose amoxicillin. Amoxicillin–clavulanate if recent amoxicillin use or if no response amoxicillin. Alternatives: cefuroxime, loracarbef, cefprozil, cefdinir, cefixime.
What is the treatment of sinusitis in patients with severe penicillin allergies?,
Patients with severe penicillin allergies should receive azithromycin or clarithromycin. Levofloxacin, moxifloxacin, or gatifloxacin are acceptable.
What are the causes of pharyngitis?,
Usually viruses; group A beta–hemolytic streptococci (S. pyogenes) may cause rheumatic fever or glomerulonephritis. S. pyogenes causes 15–20% of cases of pharyngitis.
What is the presentation of pharyngitis?,
Sore throat with cervical adenopathy and inflammation of the pharynx with an exudate is highly suggestive of S. pyogenes. Viruses do not cause an exudate.
How is pharyngitis diagnosed?,
Rapid Streptococcal antigen test is 60–100% sensitive and >95% specific. A positive test can be considered the equivalent of a positive culture, whereas a negative test should be confirmed with a culture.
What is the treatment for pharyngitis?,
Penicillin or amoxicillin. Azithromycin, clarithromycin, and oral, second–generation cephalosporins are alternatives in penicillin–allergic.
What is influenza?,
A systemic viral illness from influenza A or B, usually occurring in an epidemic pattern, leading to sinusitis, otitis media, bronchitis, and pneumonia.
What is the presentation of influenza?,
Fever, myalgias, headache, and fatigue. Upper respiratory symptoms predominate. Coryza, nonproductive cough, sore throat, and conjunctival injection.
How is influenza diagnosed?,
Rapid antigen detection methods of swabs or washings of nasopharyngeal secretions. Viral culture.
What is the treatment for influenza?,
Specific antiviral medications for both influenza A and B are the neuraminidase inhibitors: oseltamivir and zanamivir. Amantadine and rimantadine are only effective against influenza A.
What are the indications for influenza vaccinations?,
>50 chronic lung and cardiac disease, pregnant in the second and third trimesters; chronic facilities, health–care workers, immunosuppressed, diabetes, renal dysfunction. Contraindicated in allergy to eggs.
A 63–year–old man with a cough sputum smoked 30 years. Temperature of 100 degrees F. Chest x–ray is normal. What is the diagnosis?,
Bronchitis
What are the causes of bronchitis?,
Viruses. Small percentage caused by M. pneumoniae, C. pneumoniae, B. pertussis. Most common organisms responsible for chronic bronchitis are S pneumoniae, H influenzae, and Moraxella. CXR normal.
What is the treatment for acute exacerbations of chronic bronchitis?,
Amoxicillin, doxy, or TMP/SMZ. Patients not responding to amoxicillin should be treated with amoxicillin/clavulanate, clarithromycin, azithromycin, 2nd/3rd–gen cephalosporins, or gatifloxacin, levofloxacin, or moxifloxacin.
A 65–year–old alcoholic with cough, sputum, fever. Lost 15 pounds. Febrile. Poor dentition. Putrid, foul breath. CXR: cavitary lesion. What is the diagnosis?,
Lung abscess.
What is a lung abscess?,
Necrosis of the pulmonary parenchyma caused by microbial infection.
What is the bacteriology of lung abscesses?,
90% anaerobes. Peptostreptococcus, Prevotella, and Fusobacterium species (oral anaerobes). Aerobic bacteria, most frequently are S. aureus, E. coli, Klebsiella, and Pseudomonas.
What conditions predispose to lung abscess?,
Association with periodontal disease or aspiration (e.g., altered sensorium, seizures).
What is the presentation of lung abscess?,
Fever, cough, chest pain; putrid, foul–smelling sputum in 60–70%; chronic course with weight loss and fatigue.
How is lung abscess diagnosed?,
Sputum Gram stain and culture. Cavitary lesion. Lower lobes in upright patients, and the posterior right upper lobe in supine patients. Aspiration of abscess fluid is necessary for diagnosis.
What is the treatment of lung abscess?,
Clindamycin has good empiric coverage for the above the diaphragm anaerobes. Penicillin is also acceptable.
What conditions predispose to pneumonia?,
Cigarette smoking, diabetes, alcoholism, malnutrition, obstruction from tumors, and immunosuppression. Neutropenia and steroid use predispose to Aspergillus infection.
What is the most common cause of community–acquired pneumonia in all groups?,
S. pneumoniae (viruses
What conditions predispose to Haemophilus influenzae pneumonia?,
Smokers, COPD.
What factors are associated with Mycoplasma pneumonia?,
Young, otherwise healthy patients.
What conditions predispose to Legionella?,
Epidemic infection in older smokers, particularly when located near infected water sources, such as air–conditioning systems.
What conditions predispose to Pneumocystis jiroveci pneumonia?,
HIV–positive persons with
What conditions predispose to Coxiella burnetii (Q–fever) pneumonia?,
Exposure to animals, particularly at the time the animals are giving birth.
What condition predisposes to Klebsiella pneumonia?,
Alcoholics
What condition predisposes to Staphylococcus aureus pneumonia?,
Occurs after viral syndromes or viral bronchitis, especially influenza
What condition predisposes to Coccidioidomycosis pneumonia?,
Exposure to the deserts of the American Southwest, particularly Arizona
What conditions predispose to Chlamydia psittaci pneumonia?,
Bird exposure.
What conditions predispose to Histoplasma capsulatum pneumonia?,
Exposure to bat or bird droppings, spelunking (recreational cave exploration)
What are the clinical signs of Bordetella pertussis pneumonia?,
Cough with whoop and post–tussive vomiting.
What conditions predispose to Francisella tularensis pneumonia?,
Hunters or exposure to rabbits, bioterrorism.
What activity predisposes to severe acute respiratory syndrome (SARS, Avian influenza pneumonia)?,
Travel to southeast Asia.
Which bacteria may be utilized in bioterrorism?,
Bacillus anthracis, Yersinia pestis, and Francisella tularensis.
What is the clinical presentation of pneumonia?,
Cough, fever, sputum, dyspnea. Bacterial infections (pneumoniae, Haemophilus, Klebsiella) have purulent sputum. S. pneumoniae causes rusty hemoptysis.
What are the characteristics of the sputum in Klebsiella pneumonia?,
Klebsiella pneumoniae sputum is like currant jelly.
What are the characteristics of pneumonia caused by Pneumocystis jiroveci, viruses, Mycoplasma, and Legionella?,
Interstitial infections are caused by Pneumocystis jiroveci pneumonia, viruses, Mycoplasma, and Legionella; often cause nonproductive or dry cough.
What type of pain is associated with pneumococcal pneumonia?,
Pleuritic pain is associated with lobar pneumonia, caused by Pneumococcus, because of inflammation of the pleura. S. pneumoniae usually causes a lobar pneumonia with pleural effusion.
What are the physical signs of pneumonia?,
Rales, rhonchi, lung consolidation, dullness to percussion, bronchial breath sounds, increased vocal fremitus, egophony. Severe pneumonia leads to hypoxia.
What is the presentation of Mycoplasma pneumonia?,
Dry cough and chest soreness. Bullous myringitis; anemia from hemolysis from cold agglutinins. Rarely need to be admitted to the hospital.
What is the presentation of Legionella pneumonia?,
Confusion, headache, and lethargy. Diarrhea and abdominal pain.
What is the presentation of Pneumocystis jiroveci pneumonia?,
Marked dyspnea, particularly on exertion, with chest soreness with cough in an HIV–positive person with a CD4 count of
Which types of pneumonia are associated with interstitial infiltrates?,
Interstitial infiltrates are associated with PJP, viral, Mycoplasma, Chlamydia, Coxiella, and Legionella pneumoniae.
What is the most specific test for lobar pneumonia?,
Sputum culture and Gram stain. S pneumoniae, Staph, Klebsiella, Haemophilus. Viral, Mycoplasma, Chlamydia, Coxiella (atypicals) will not appear on a Gram stain or bacterial culture.
What is the best diagnostic method for Mycoplasma pneumonia?,
Specific serologic antibody titers. Cold agglutinins have limited specificity and sensitivity.
What are the diagnostic methods for Legionella pneumonia?,
Charcoal yeast extract media, urine antigen tests, direct fluorescent antibodies, and antibody titers.
What is the best diagnostic method for Pneumocystis jiroveci pneumonia?,
Bronchoalveolar lavage; increased LDH.
What is the best diagnostic method for Chlamydia pneumoniae, Coxiella, Coccidioidomycosis, and Chlamydia psittaci?,
Specific antibody titers.
What are the signs of severe pneumonia?,
pO2 30, disorientation, uremia, systolic BP 125), hyponatremia, dehydration, elevated BUN.
Which pneumonia patients should be hospitalized?,
Patients with severe pneumonia or serious underlying diseases such as cancer, liver disease, renal disease, or chronic lung disease should be hospitalized for intravenous medications.
What is the empiric therapy for outpatient pneumonia?,
Macrolide, azithromycin or clarithromycin. Levofloxacin, moxifloxacin, gatifloxacin are alternatives. Cephalosporins and amoxicillin/clavulanate do not cover atypical pathogens.
What is the treatment for hospitalized patients with community–acquired pneumonia?,
Levofloxacin, moxifloxacin, or gatifloxacin or cefotaxime or ceftriaxone combined with a macrolide such as azithromycin or clarithromycin (or doxycycline).
What organisms cause hospital–acquired pneumonia?,
Drug–resistant, Gram–negative bacilli (Pseudomonas, Klebsiella, E. coli), or gram–positives, including methicillin–resistant Staphylococcus aureus.
