Infectious Diseases Flashcards
Serious bacterial infection may present as? High-risk groups?
Meningitis, pneumonia, sepsis, osteomyelitis, UTI, enteritis
- Young infants younger than 28 days
- Older infants with temperature >39
- Immunodeficient children
- Sickle cell disease
- Chronic liver/renal/lung/cardiac disease
Microbiologic stains?
- Gram stain
- Ziehl-Neelson (Acid-fast bacilli)
- Silver stain (fungi)
- Wright stain (stool WBCs)
Typical pathogen and empiric antibiotics for patient aged less than one month? 1-3 months? Three months to three years? Over three years?
Group B strep, E. coli, Listeria (ampicillin + gentamicin OR cefotaxime)
Group B strep, pneumococcus, Listeria (ampicillin + cefotaxime)
Pneumococcus, H. influenzae, meningococcus (cefotaxime)
Pneumococcus, meningococcus (cefotaxime)
When to hospitalize an infant for fever?
- Less than 28 days old
- Toxic appearance
- Meningitis suspected
- Pneumonia, pyelonephritis, bone/text soft tissue infections which are UNRESPONSIVE to oral antibiotics
- Uncertain outpatient care and follow up
Patient presents with fever – plan if toxic? If nontoxic with fever over 39? Non-toxic with fever under 39?
If toxic appearing – evaluate for sepsis, IV antibiotics, hospitalize
It’s nontoxic-appearing and temperature over 39° – get URINE CULTURE (from males under six months or females under two years), BLOOD CULTURE, CXR (if respiratory distress or tachypnea), STOOL CULTURE (if blood/mucus in stool or over five wbc’s), empiric ANTIBIOTICS
If nontoxic-appearing and temperature under 39° – child stays home
Definition of fever of unknown origin?
Fever lasting longer than one to three weeks
Laboratory tests for fever of unknown origin?
CBC, ESR/CRP, transaminases, UA/urine culture, blood cultures, ASO titers, AMA/RF, PPD, HIV, stool culture/toxins
Bacterial meningitis in children – risk factors? Symptoms?
- Young age
- Immunodeficiency (asplenia, humoral immunodeficiency, complement deficiency)
- Anatomic defects (basilar skull fracture, ventriculoperitoneal shunt)
Infants – poor feeding lethargy, respiratory distress, bulging fontanelle, fever not necessary
Older children – and Klupenger Diddy, seizures, photophobia, headache, emphasis
Bacterial meningitis – LP findings? Other tests? Possible complications? Tx - give what to everyone? Give what else based on age?
- Lumbar puncture (WBC >5000, glucose ratio under 40%, increased protein, positive Gram stain)
- Blood culture
- CT scan with contrast
- Hearing loss
- Global brain injury
- SIADH, nerve palsy, seizures, hydrocephalus
Steroids for all and:
- Newborns – ampicillin plus aminoglycoside/Ceftriaxone
- Young infants – ampicillin plus ceftriaxone and vancomycin
- Older children (greater than three months) ceftriaxone and vancomycin
Aseptic meningitis? Causes?
Inflammation of the meninges with lymphocytic pleocytosis, normal glucose, normal CSF protein
- Viral - enteroviruses, mumps, herpes,
- Bacterial – TB, Borrelia, treponema
- Fungal – Coccidioides, Cryptococcus, histoplasmosis
- Parasitic – taenia, Toxoplasma
Diagnosis of viral meningitis? TB meningitis?
Viral culture, PCR, surface cultures from throat/rectum (for enterovirus)
Basilar enhancement on brain imaging, AFB stains, PCR findings
Causes of URI? Management? When to evaluate for bacterial superinfection?
Rhinovirus, parainfluenza virus, coronavirus, RSV
Low-grade fever, rhinorrhea, cough, sore throat
Adequate hydration
Persistent symptoms (>10 days) or fever should warrant evaluation for bacterial superinfection (sinusitis, acute otitis media)
Development of sinuses?
- Ethmoid and maxillary sinuses – present at birth (3rd-4th month of gestation)
- Sphenoid sinuses – 3-5 years
- Frontal sinuses – 7-10 years
Types of sinusitis? – Clinical features?
- Acute persistent (nasal discharge, cough for 10-30 days, headache, facial pain, fever)
- Acute severe sinusitis – fever >39 with purulent nasal discharge for 30-90 days
- Subacute sinusitis – acute persistent sinusitis for 30-90 days
- Chronic sinusitis – acute persistent sinusitis lasting longer than 90 days
Sinusitis – etiology? Management?
for acute persistent, acute severe, subacute:
- Strep pneumo, H flu, Moraxella
- Amoxicillin, Augmentin, second-generation cephalosporin
For chronic sinusitis:
- Underlying condition (cystic fibrosis, allergy, immunodeficiency)
- Staph aureus plus anaerobes
- Broad-spectrum antibiotics, CT imaging, IV antibiotics
Viral pharyngitis – causes? Clinical features? Management?
- URI viruses – rhinovirus, parainfluenza, coronavirus, RSV
- Coxsackie, EBV, CMV
- URI symptoms
- Tonsillar exudates
- If EBV – enlarged posterior cervical lymph nodes and hepatosplenomegaly
- If Coxsackie – herpangia (painful vesicles on the posterior pharynx) or hand-foot-mouth
- Analgesics and hydration
- Severe EBV – corticosteroids
Bacterial pharyngitis – causes? Clinical features? Diagnosis? Management?
Streptococcus Pyogenes, group B strep, arcanobacterium, Corynebacterium.
- Group B-strep – ages 5 to 15, no rhinorrhea, no cough, tonsillar exudate, petechia on the soft palate, strawberry tongue, anterior cervical went nodes, fever,
- Diphtheria – Gray, adherent Tonsilar membrane, cardiac/neuro complications
Group B-strep: culture (gold standard) or antigen testing
Group B-strip: oral penicillin, benzathine penicillin, macrolides
2. Diptheria - erythromycin or parenteral penicillin plus specific antitoxin
Acute otitis media – Causes? Clinical features? Diagnosis? Management?
Acute otitis media – infection of middle ear space
Strep pneumonia, nontypeable H. influenzae, Moraxella, viral
- Fever, ear pain, decreased hearing
- Develops during/after URI
- If Tympanic membrane perforates pus draining from ear
- Diagnosis needs fluid in middle ear (Pneumatic otoscopy) with symptoms of infection (erythema and loss of tympanic membrane landmarks)
- Tympanocentesis
- Purulent discharge from external auditory canal
- amoxicillin
- If patient attends day care or has received antibiotics within the last two months, use augmentin or cephalosporin
Otitis media with effusion?
Fluid within middle ear space without symptoms of infection
Otitis Externa – definition? Pathogenesis? Causes? Clinical features? Diagnosis? Management?
Infection of external auditory canal
Cerumen removal, trauma, swimming,
Pseudomonas, staph aureus, candida, perforated tympanic membrane
Pain, itching, Drainage,
Erythema/edema with purulent material and tenderness to movement of the ear
- Restore acidity – Acetic acid solution
- Topical antibiotics
- If perforated tympanic membrane, add oral antibiotics
Cervical lymphadenitis – causes? Clinical Features? Diagnosis? Management?
- Staph aureus is the most common
- Strep Pyogenes , Mycobacterium,
- Bartonella
- reactive lymphadenitis
- Viral – EBV, CMV, HIV
- Kawasaki
- Toxoplasma
- Structural (Branchial cleft cyst, cystic hygroma)
Lymph node is mobile, tender, warm, enlarged with erythema
CBC, PPD, anti-body titers, imaging
- Empiric antibotics, (First-generation cephalosporin or anti-staff penicillin)
- IV antibiotics for toxic appearing child or child who remains symptomatic
Parotitis - causes? Clinical features diagnosis? Diagnosis? Tx? Complications?
- Bilateral involvement – mumps, CMV, EBV, HIV, influenza
- Unilateral involvement – staph aureus, strep pyogenes, TB
- Swelling above angle of jaw and fever
- Pus from Stensen’s duct
- CT scan
- Culture from Stensen’s duct or viral serology (mump’s virus detected in urine)
Supportive care, antibiotics against staph and strep
- Meningioencephalitis, orchitis, epididymitis, pancreatitis,
- If bacterial: osteomyelitis of jaw
Impetigo – causes? Clinical features? Diagnosis? Management? Complications?
Staph aureus >GABS/strep Pyogenes
Honey colored cresting lesions
Visual inspection (new cultures required)
Oral antibiotics (dicloxacillin, clindamycin)
- Poststreptococcal GN
- Staph Scalded skin symptoms
Erysipelas – Definition? Cause? Critical features? Diagnosis? Management?
Skin infection involving dermal lymphatics
GABHS
Tender, erythematous skin with distinct border
Visual inspection
Systemic antibiotics against GABHS
Cellulitis – definition? Causes? Features? Diagnosis? Management?
Infection of the dermis
GABHS, staph aureus
Erythematous, tender, indistinct borders
Visual inspection, biopsy/culture of leading edge
First generation cephalosporins or anti-staph penicillins
Variations on cellulitis?
Buccal cellulitis – unilateral bluish discoloration of cheek and you guys child calls by H. influenzae. Performed lumbar puncture
Perianal cellulitis – rash around anus constipation. GABHS. Dicloxacillin, cephalexin.
Necrotizing fasciitis – pain out of proportion to physical findings. Infection extends beyond underlying fascia to muscle. Crepitus and hemorrhagic bullae. Polymicrobial. IV antibiotics and surgical debridement
Scolded skin syndrome – staph aureus. Positive Nikolskiy sign. IV antibiotics
Scarlet fever – cause? Peak incidents? Transmission? Critical features? Diagnosis? Management? Complications?
GABHS; winter/spring; respiratory droplets
- Prodrome of fever, chills, malaise
- Exanthem (Begins on trunk, erythematous, sandpaper rash, Pastia’s lines (linear petechia), desquamation)
Positive throat culture or positive rapid strep test
penicillin or macrolides
Complications of GABHS infections?
- Post streptococcal GN – not prevented by antibiotics
- Poststreptococcal arthritis (not prevented by antibiotics)
- Dynamic fever (prevented with antibiotics)
- PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcus) – OCD or to tic disorder after strep infection. Prevented by antibiotics
Toxic shock syndrome – causes? Clinical features? Management?
Staph aureus and GABHS, tampons
Probable if 5/6, definite if 6/6:
- Fever over 38.5
- Hypotension
- Diffuse macular erythroderma
- Desquamation
- Negative blood cultures, CSF, pharynx
- Multisystem and hopefully including three of: G.I., joints, mucous membranes, sterile pyuria, thrombocytopenia, CNS
Antibiotics, IVIG,
