ID Flashcards
Lyme disease
Carrier/Type/Bug + Drug, Sx (early and late), Dx
Carrier: Lxodes scapularis tick
Type: Spirochete
Bug: Borrelia burgdorferi
Sx:
Early: erythema migraines, uni/bilateral CN VII palsy, meningitis, carditis, migratory arthralgia
Late: Arthritis (afebrile, well appearing, can bear weight), encephalitis, peripheral neuropathy
Dx: ELISA and Western blot analysis
Drug:
- 1st line: Doxycycline.
- Amoxicillin or cefuroxime for children and pregnant woman
- If treating for <21 days, patients <8 can use doxy
Syphilis
Type/Bug
Early congenital manifestation
Tx with stages
Reaction with treatment
Type: Spirochete
Bug: Treponema pallidum
Early Congenital features:
- Perinatal: Fetal demise, prematurity, low birth weight, focal necrosis of umbilical cord
- Mucocutaneous: snuffles, desquamating/maculopapular rash, fissures near orifices, jaundice
- MSK: Long bond abnormalities
- Reticuloendothelial: hepatosplenomegaly, lymphadenopathy, anemia, thrombocytopenia, leukopenia/leukocytosis
Neurosyphilis
- Asx at first –> HA, blurry vision
- Dx: LP
- Rapid plasma reagin titers >1:129
Drugs
- Primary and Secondary: Benzathine Pen G IM (single dose)
- Latent (>12mo): Benzathine Pen G IM once weekly for 3 weeks
- Neuro/tertiary: Aqueous Pen G IV every Q4H for 10-14days
- Congenital: Aqueous Pen G IV Q8-12H for 10 days
Jarisch-Herxheimer reaction: acute febrile syndrome within 24hrs of treatement. No prevention, self-resolve within 48hrs. If sever, can be given acetaminophen.
Malaria
Carrier/Type/Bug + Drug
Why is P. Falciparum different
Something about vivax and ovale
Carrier: Mosquito
Type: Parasite
Bug: Plasmodium
Plasmodium falciparum: most severe because it can infect erythrocytes –> parasitemia. Erythrocytes form sticky membrane knobs –> bind to receptors on endothelial cells in capillaries and small venules –> partial vessel occlusion, inflammation, and organ dysfunction. Also have phases in RBC and the liver.
Plasmodium vivix and ovale form dormant hypnozoites in the liver
Drug:
Chloroquine (intraerythrocytic phase) + Primaquine (dormant hepatic phase)
Combo to prevent relapse
Viral meningoencephalitis
Bugs, Dx + Drugs
Bugs: Coxsackie (enterovirus) most common, HSV (herpes), West Nile (arbovirus)
Dx: LP –> CSF aseptic pleocytosis, viral serologies
Drug: supportive, Acyclovir for HSV, Vanco, 3rd gen cephalosporin empirically
UTI
Recurrent definition, prevent, ppx
Recurrent definition: >2 in 6 months or >3 in 1 years
Prevent: genital hygiene, increased fluid intake, postcoital voiding, avoid spermicides
Tx:
PPX: Trimethoprim-sulfamethoxazole (bactrim), nitrofurantoin, and cephalexin
HIV
Reporting guidelines
PCP : CD#, Dx, Tx
Physicians are required to report + HIV test to Department of Health but not always to the 3rd party (depends on the state)
Pneumocystis jirovecii pneumonia (PCP)
- CD4 <200
- Dx: Induced sputum cultures are accurate 50-90% of the time. Bronchiolar lavage is most accurate.
- Tx: Trimethoprim-sulfamethoxazole + Steroids.
Resp decompensation is common during first 2-3 days of tx d/t organism lysis –> inflammation. Steroids indicated if A-a gradient is >35 and PaO2 <70
Chikungunya
Carrier/Bug, Sx, Tx
Carrier: Aedes mosquitoe :
Bug: Alphavirus
Sx: fever, joint pain, conjunctivitis, rash
Tx: supportive, chronic pain tx with MTX
Helminths
3 types, Sx, Comp, Labs,Dx,Tx
Ascaris lumbricoides (roundworm)
Trichuris trichiura (whipworm)
Ancylostoma duodenale or Necator americanus (hookworm)
Sx: Pulmonary (cough, dyspnea), GI (N/V,abd pain, diarrhea)
Comp: Surgery if causes obstruction
Labs: Eosinophilia , + fecal occult blood
Dx: O & P
Tx: Albendazole, Mebendazole is better for whip worms)
C. Diff
RD, 3 levels and Tx
RF: Antibiotics, Gastric acid suppression, Hospitalization, Age >65
3 levels:
- Nonsevere
- Severe: leukocytes >15,000 and creatinin >1.5
- Fulminant: severe with hypotension, ileus or megacolon, necrosis leading to perforation
Tx:
- Nonsevere and severe: 10 days of Oral Fidaxomicin or Vancomycin. Oral Metronidazole 3rd line.
- Fulminant: Oral Vanco + IV Metronidazole
- Refractory: fecal transplant, surgical intervention
- NO STEROIDS
Erythema mulitform
Associated Bugs, Description
Associated infection: HSV, Mycoplasma pneumo
- Target lesions on skin: erythematous well-defined borders, with pale/dusky center that is often bullae/ulcerated
- Painful bullae or erosions on mucosa
- Not transmissible from person to person
Tx:
Acute: supportive, possible topical steroids
Recurrent: suppressive antiviral therapy
Animal bites
Oral flora of animal: Pasteurella or oral anaerobes
Skin flora: Strep pyogenes or Staph aureus
HPV
Virus type, subtypes for cancer, How it works
Plantar wart treatment
Cervical cancer (4)
dsDNA
16 and 18 associated with cancer
These oncogenes integrate in host genome and produced viral protein E6 and E7 which interact with p53 and Rb respectively –> inhibit cell cycle regulation
Plantar warts (with thrombosed capillaries)
Tx: Salicylic acid and cryotherapy , can 1-2 months for resolution.
Shave or punch biopsy rarely needed.
Cervical cancer
- CIN 1 (low grade): dysplasia confined to lower 1/3 of cervical epithelium
- CIN 2/3 (high grade): no extending towards epithelial surface. Have a higher risk of progressing to invasive carcinoma.
- Invasive cell carcinoma: basement membrane invasion
- Cervical adenocarcinoma: atypical grandular cells invading BM
HHV-3
Who is immune, Tx, postexposure tx - 3 types, when infectious,
HHV-3 Varicella (chickenpox) Zoster (shingles )
- Zoster: unilateral dermatomal rash, crust over in 7-10 days
- Tx: 7 days course of valacyclovir
- Immune if previously had varicella or received varicella vaccine.
- If not immune: Varicella vaccine within 5 days
- Not immune and immunocompromised or pregnant: Also need immune varicella-zoster globulin or antiviral therapy.
- Zoster vaccine only given if >50y/o
- Not as infectious once crusted over
- Pain treatement: NSAIDs –> gabapentin, pregabalin, TCAs
Tetani
Bug/Type, Path, Sx, Prevention MOA
Clostridium tetani
Gram Positive rod
Anaerobic
Path: Produced neurotoxic exotoxin called tetanospasmin (tetanus toxin) that travels retrograde to CNS –> blocks inhibitory neurotransmission
Sx: increase muscle tone, lockjaw, painful spasms
MOA of vaccine: humoral antibody response against tetanus toxin
TB
Dx
Pleural effusion sx, fluid component, Dx
Sx: Can cause a pleural effusion –> fever, cough, pleurisy and weight loss.
Thoracentesis can be positive for adenosine deaminase
Pleural fluid smear is normally aseptic so pleural biopsy is needed for diagnosis
Dx:
Screening test: Tuberculin skin test is generally positive in patient with active TB because lymphocytes recognize injected tuberculin antigens and trigger a strong type IV hypersensitivity response. However, ~25% of patients have false negative d/t impaired lymphocyte response –> minimal or no induration. False negative can also be seen in recent infection, immunocompromised, improper injection technique, or natural waning of immunity.
Confirm test: sputum sample
