ID/Immuno Flashcards
Neonatal HSV - presentation and prognosis
- Localized skin, eye, and mouth, excellent prognosis (clear vesicles on erythematous base)
- CNS with or without localized skin, eye, mouth - 15% mortality, with more than half having persistent neurologic sequelae; use of suppressive acyclovir for 6mo can improve outcomes
- Disseminated HSV makes up 25% of infections, multiple organs affected; necrotizing hepatitis, mortality >85% without treatment
Antibiotics for acute chest syndrome?
Ceftriaxone and azithromycin
Mnemonic for Kawasaki?
CRASH and Burn - conjunctivitis, rash, adenopathy, strawberry tongue, hands/feet + fever
What are criteria for HLH?
(5 of 8 criteria)
- Persistent fever
- Splenomegaly
- Cytopenias (Hgb<9, neutrophils<1K, platelets<100K)
- Hypofibrinogenemia <150 or hypertriglyceridemia >265
- Hyperferritinemia >500
- Hemophagocytosis
- Low NK cell activity
- High soluble IL2 receptor
Treatment for familial HLH?
Stem cell transplant or emapalumab (monoclonal antibody inhibiting interferon gamma)
What are malaria symptoms?
Periodic fever every 23 days coinciding with erythrocyte rupture. Influenza like symptoms: chills, myalgia, lethargy, nausea, abdominal pain, headaches, cough
Disease progression due to anemia and end-organ damage resulting from vascular adherence of infected erythrocytes with capillary occlusion, can have CNS involvement, kidney, and lung. Anemia, hemoglobinuria, metabolic acidosis, hypoglycemia.
Mosquito injects malaria, travels to liver, replicates, liver cells burst, travel to RBCs, RBC rupture causing symptoms
Malaria treatment
In US, uncomplicated P falciparum treated with 3-day course of artemether-lumefantrine
P vivax or P ovale treated with 14d primaquine to cover latent liver stages
Severe malaria: IV artesunate (favored, need CDC approval), quinine (not available in US), or quinidine gluconate (most likely first available)
What is the treatment for primary amoebic ecenphalitis?
Amphoterocin B, rifampin can potentiate effects
Additional: steroids, increased ICP management, seizure prophylaxis
Naegleria fowleri, usually fatal, fresh warm water environments (ponds, lakes, rivers, hot springs)
Similar symptoms to other meningitis, may have hemorrhage or cerebral edema on imaging
Top three pathogenic bacteria from gut translocation?
Escherichia coli
Klebsiella
Pseudomonas aeruginosa (gram negative aerobic bacilli)
Lemierre syndrome definition and treatment
complication of pharyngitis with resultant bacteremia, thrombophlebitis of the internal jugular vein, and subsequent septic emboli
Metronidazole for fusobacterium
Anticoagulation should be considered in Lemierre syndrome when there is little clinical improvement with antibiotics alone, propagation of the primary thrombus, evidence of thrombophilia, or presence of cavernous sinus thrombosis or other intracranial thrombus formation
Most common viruses associated with bronchiolitis?
- RSV
- Rhinovirus
- Adenovirus
- Human metapneumovirus
Toll Like Receptors
In central nervous system infections, toll-like receptors 2, 4, and 9 appear to have a primary role in bacterial meningitis, whereas toll-like receptors 3, 7, 8, and 9 play a more prominent role in viral encephalitis.
What is Pott puffy tumor?
complication of frontal sinusitis
bacterial sinusitis extends into frotal skull bone, causig osteomyelitis by direct extension/erosion or hematologic spread- subdural abscess or empyema
Steroids WITH THE FIRST DOSE OF ANTIBIOTICS (has to be in first hour) may be beneficial for bacterial meningitis with what organism?
H influenzae B (reduces neurologic sequelae and hearing loss)
Consider adding rifampin to vanc/cefepime because dexamethasone can impact BBB penetration of vanc
No confirmed benefit for S pneumoniae or N meningitidis
Most common microbial cause of necrotizing faciitis?
Streptococcus pyogenes (Group A strep)
First line treatment: surgical debridement (abx can’t penetrate necrotic tissue because of poor vascular supply)
Can be mimic’d by ecthyma gangrenosum - Pseudomonas bacteremia where bacteria invades vessel wall causing ischemia/necrosis, usually immunocompromised
Role of IVIG in toxic shock?
Neutralization of bacterial superantigens
treat with beta lactam (inhibition of cell wall synthesis), clinda (inhibition of protein synthesis) and IVIG
Signs and symptoms of DRESS (drug reaction with eosinophilia and systemic symptoms)
Almost all: fever, rash (absent mucosal involvement), and lymphadenopathy; eosinophils and atypical lymphocytes
facial edema, hematological abnormalities, multiple organ involvement (transaminitis, AKI)
2 weeks to 2 months after new medication, can often have recurrence even when medication isn’t restarted
Pathogenesis: type IV reaction, T-cell mediated, may also see reactivation of latent HSV, EBV, or CMV
Myalgias, fever, rhabdo, renal failure, myocarditis
Influenza
Treatment for refractory CNS vasculitis?
TNF-blockade (infliximab)
Sphygmothermic dissociation - definition and associated infections
Relative bradycardia in setting of significant fever (Faget sign)
Babesiosis, Rocky Mountain spotted fever, Legionella, Leptospirosis, typhoid, yellow fever, brain abscess
Signs and symptoms of yellow fever
Transmitted by mosquitoes
Incubation 3-6 days
Fever, muscle pain, headache, anorexia/nausea, vomiting
Second phase: fever recurrence, jaundice, dark uring, vomiting, hemorrhage, hepatic failure, often renal failure
Faget sign - relative bradycardia with fever
Vaccine but no specific treatment
Lab findings in PJP
LDH high
Beta-D-glucan high
Can send BAL sample or sputum sample for PCR
Treatment: Bactrim, steroids
