Infectious diseases Flashcards
high-risk conditions that increase risk of bacteremia
sickle cell, asplenia, malignancy, chemo, HIV, renal disease, prolonged steroid use, central lines/ indwelling catheters, VP shunts
Risk factors for UTI
febrile, white girls < 2 years old, and uncircumcised boys before toilet training. Previous UTI
Toxicologic causes of fever
serotonin syndrome, neuroleptic malignant syndrome, ASA, anticholinergics, sympathomimetics
Low risk criteria for fever in 1-2 month old infants
full term (> 37 weeks) no prolonged NICU stay no chronic medical problems no recent Abx in last 3 days well-appearing no focus on exam, WBC 5-15, Band/neut ratio < 0.2; Urine < 10 WBC/hpf, CXR no infiltrate (if done for resp symptoms)
Antibiotic choices for sepsis in < 1 month old
ampicillin and gentamycin (cefotaxime if meningitis)
Antibiotic choices for fever in 30-90 days
cefotaxime, vancomycin +/- ampicillin
Cervical lymphadenopathy - acute bilateral causes
resp viruses, enterovirus, adenovirus, EMV, CMV
Cervical lymphadenopathy - acute unilateral causes
S. aureus, S. pyogenes
Cervical LN - chronic unilateral causes
atypical mycobacteria, TB, bartonella Henselae
Risk factors for toxic shock syndrome
recent tampon use (prolonged/ high absorbency), recent surgery, and recent infection (involving skin or soft tissue or other site). Burns, steroids, malignancy, DM2, immunocompromised, IVDU
Treatment of Toxic shock syndrome
Cloxacillin + clindamycin
IVIG for GAS TSS
Classic triad of RMSF?
Fever, rash and headache
Treatment of RMSF?
doxycycline
When to do a CT scan before LP in meningitis?
focal neuro deficit, papilledema, history focal neuro disease, immunocompromised, signs cerebral herniation
3 types of neonatal HSV
- Skin, eye, mouth
- CNS
- Disseminated
Organisms that cause sinusitis
Same as AOM: pneumococcus, H. influenza, Moraxella, GAS
Complications of sinusitis
orbital cellulitis, facial cellulitis or abscess, intracranial abscess, meningitis, orbital subperiosteal abscess, cavernous sinus thrombosis, OM frontal bone with subperiosteal abscess (Pott’s puffy tumor), sinus mucocele
Clinical criteria for the diagnosis of sinusitis?
- Persistent > 10 days
- Worsening course
- Purulent nasal drainage (3 days) and fever
Complications of mastoiditis?
intracranial spread (abscess), bacteremia, facial nerve damage, labyrinthitis, osteomyelitis
Pathophysiology of tetanus?
bacteria enters wound and produces tetanus toxin that travels to the brainstem and spinal cord –> disrupts synaptic transmission by preventing release of neurotransmitters
o loss of inhibition (ie, disinhibition) of anterior horn cells and autonomic neurons results in increased muscle tone, painful spasms, and widespread autonomic instability
o may lead to life-threatening respiratory failure and autonomic dysregulation in severe cases
Incubation period of tetanus?
3-21 days
4 forms of tetanus?
o Generalized tetanus
o Local tetanus: tonic and spastic muscle contraction in one body extremity
o Cephalic tetanus: cranial nerve involvement (facial nerve)
o Neonatal tetanus: refusal to feed and difficulty opening mouth, facial muscle spasm, tonic contraction
Treatment of botulism?
Supportive, intubation if needed
o For infants: baby botulism immunoglobulin (BabyBIG), no antibiotics
o For children: botulinum antitoxin, and pencillin or flagyl
Treatment of tetanus?
Tetanus immunoglobulin (TIG) with some infiltrated into the wound and the rest IM; flagyl or penicillin 10-14 days
o Intubate + large doses of sedatives to reduce spasms/ laryngospasm
o Large doses of benzos
Etiology of pneumonia?
- Viral causes are most common
- Bacterial: pneumococcus, S. aureus, GAS
Indications for hospital admission for pneumonia?
< 3-6 months old, immunocompromised, no response to PO abx after 1-2 days, dehydration, suspected staph pneumonia (empyema, pneumatocele), O2 need, unstable vitals
What is Light’s criteria for exudative pleural effusion?
pleural fluid:serum protein ratio > 0.5
pleural fluid:serum lactate dehydrogenase (LDH) ratio > 0.6
pleural LDH concentration > 2/3 the normal upper limit for serum
Transudative pleural effusion causes (list 4)
CHF, Cirrhosis, Nephrotic syndrome, Malnutrition causing low protein state, IBD, Peritoneal dialysis, Sarcoidosis, SLE, Pulmonary embolism
Stages of pertussis?
- First stage = catarrhal phase: 1-2 weeks; similar to URTI; mild cough, conjunctivitis, coryza
- Second stage = paroxysmal stage = 2-4 weeks; prolonged spasm of coughing and characteristic whoop cough from inflow of air; posttussive emesis common; may become cyanotic, anxious
- Third stage (convalescent): intensity of cough wanes
Complications of pertussis?
complete airway obstruction from mucous plug leading to respiratory arrest, bacterial pneumonia, apnea, seizure, encephalitis, intracranial hemorrhage, rectal prolapse, rupture diaphragm
Infectious DDx of Kawasaki?
viral (adenovirus, EBV, CMV), scarlet fever, Staph scalded skin, TSS, ricketsiall disease (RMSF), leptospirosis.
Treatment of pertussis?
Azithromycin x 5 days
Chemoprophylaxis for household contacts (azithromycin or erythromycin), booster if not fully immunized
Which organisms cause endocarditis
S. aureus, S. viridans, HACEK organisms (haemophilus, actinobaccilus, cardiobacterium hominis, Eikenella, Kingella)
5 bacterial causes of gastroenteritis?
Salmonella, Shigella, Yersinia, Campylobacter, E. coli
Organisms that cause HUS?
E. Coli O157:H7 (and Shigella, pneumococcus, and campylobacter)
Treatment of HUS?
NO antibiotics, supportive care, IV fluids, platelets if life-threatening bleeding, nephrology and ICU – may need dialysis.
Complications of C. Diff?
toxic megacolon, perforation, peritonitis