Infectious Disease Flashcards
MRSA?
Px: Boil or pimple type lesion; described as “pustules on an erythematous base”.
TX: HA- IV Vancomycin
CA- Oral Clindamycin
Oral Bactrim
Sepsis?
Px: Fever, RR >20, Hypotension, WBC count less than 4,000 or greater than 12,000, HR > 90.
Dx: Lactate > 18. Respiratory alkalosis with a metabolic acidosis.
Tx: Fluid- Iv crystalloid if fails, norepi. Empiric Piperacillin-tazobactam (Zosyn) + Vancomycin.
Scarlet fever?
GABHS (Streptococcus pyogenes)
PX: Winter/Spring; “sandpaper feel” rash to neck/trunk –> UE. Pastia’s lines. strawberry tongue, circumoral pallor.
Dx: RADT/Throat cx
Tx: Amoxicillin, if ax clindamycin.
Diptheria?
Px: grayish-white membrane, bull neck, chronic non-healing ulcer, myocarditis.
Dx: Throat swab –> gram-positive rods with blue and red metachromatic granules, + Elek Test.
Tx: Diphtheria antitoxin immunoglobulin, PEN G.
Tetanus?
Gram-positive, spore-forming rod –> tetanospasmin.
Px: Trismus, difficulty in feeding
Dx: Clinical or cx or test serum anti-tetanus immunoglobulin G.
Tx: Human tetanus immune globulin (TIG) and Metronidazole.
Botulism?
gram-positive bacillus, anaerobic, spore-forming bacteria.
Raw honey, canned foods.
Px: Symmetric cranial nerve palsies and descending flaccid paralysis. “4 Ds”, diplopia, dysarthria, dysphonia, dysphagia. Floppy baby syndrome w/ hypnotic & weak cry.
Dx: Toxin Assays
Tx: Antitoxin (equine-derived heptavalent) For infant, human botulinum immunoglobulin (BIG-IV). For wound, penicillin or metronidazole.
Clostridial Myonecrosis (Gas Gangrene)?
Traumatic inoculation with Clostridium perfringens (obligate anaerobe, gram-positive rod).
Px: Intense pain, bullae and crepitus.
Dx: Clinical, X-rays = air in the soft tissues, Cx = gram-positive bacilli.
Tx: surgical debridement and excision – possible amputation IV antibiotics (Penicillin plus Clindamycin).
Cholera?
Gram-negative rod. Fecal contamination of water and food. Shellfish w/o adequate cooking.
Px: Large volumes of watery diarrhea -> “rice water stool”.
Dx: Culture
Tx: Water and electrolytes. etracyclines/fluroquinolones –> Shorten symptom duration.
Lyme?
Motile spirochete and transmitted via the Ixodes scapularis (“blacklegged”) deer tick. May to September.
Px: expanding, warm, annual, erythematous rash w/ central clearing (bull’s eye/target appearance). Facial nerve palsy, Arthritis, Cardiac block, Erythema migrans.
Dx: Clinical. ELISA -> if positive (or equivocal) then Western Blot for confirmation.
Tx: Early localized, disseminated, & prophylaxis- Doxycycline.
Preg.- Amoxicillin
Late To Severe: IV Ceftriaxone
Rocky Mountain Spotted Fever?
Rickettsia rickettsia. Gram-negative, very short rods & obligate intracellular bacteria.
Dog ticks.
Px: Macules to petechiae first on palms & wrists and soles & ankles THEN moves inward to the trunk.
Dx: Clinical. ELISA testing is used to test for IgM and IgG antibodies.
Tx: Doxycycline
Chloramphenicol is 2nd line, and used in pregnancy.
Varicella Zoster Virus (HHV-3): Chicken Pox ?
Px: Erythematous macules that become papules then vesicular (crops) then crust over on the face and then goes to the trunk before spreading to the extremities.
Scabs in various stages of evolution.
Dx: Clinical. PCR for viral DNA
Tx: Healthy children < 12: Acetaminophen & Calamine lotion. Adults, adolescents > 12, immunocompromised = acyclovir.
Varicella Zoster Virus (HHV-3): Shingles?
PX: Pain. Unilateral rash within a single dermatome that does not cross the midline. Hutchinson’s sign. Ramsay Hunt syndrome.
Dx: Same as chickenpox.
Tx: Valacyclovir
Post Post herpetic neuralgia tx = Gabapentin.
Epstein-Barr Virus: HHV-4?
infectious mononucleosis. Also associated with Hodgkin’s disease.
Px: Triad: lymphadenopathy (MC posterior cervical), splenomegaly (wk 2-3), exudative pharyngitis.
Dx: Lab tests reveal lymphocytosis w/ > 10% atypical lymphocytes (Downey cells) w/ levated LFT’s, ↑ bilirubin and
Heterophile antibody test (monospot) (wk. 3)
Tx: Supportive and Increased risk of splenic rupture so avoid contact sports.
Cytomegalovirus (CMV): HHV-5?
Px: Like mono but reactivation, Colitis: diarrhea, fever, abdominal pain, bloody stools. (MC)
Retinitis: decreased visual acuity and floaters. (important cause of blindness in AIDS)
Esophagitis: odynophagia with large superficial ulcers on upper endoscopy.
Dx: Labs w/ atypical lymphocytosis; Heterophile antibody-negative and Cytopathology: shows intracellular inclusions surrounded by a clear halo “owl eye cells”.
Tx: Primary = supportive
Reactivation = Ganciclovir but for HIV + with CD4 < 50 cells/uL, Valganciclovir is prophylactic.
Roseola Infantum: HHV-6?
Px: Fever, resolves, then rose pink, maculopapular, blanchable rash beings on the trunk and peripherally.
Dx: Clinical
Tx: Supportive
Erythema Infectiosum?
Human parvovirus B19.
Px: “slapped cheek”. Erythematous maculopapular rash on proximal extremities (usually arms and extensor surfaces) and trunk, which fades into a classic lacelike reticular pattern.
Dx: clinical, IgM/IgG serology and PCR assay can be performed if pregnant/immunocompromised.
Tx: Symptomatic