Infectious Diseases

Question 0

Serious bacterial infection may present as? High-risk groups?

Answer 0

Meningitis, pneumonia, sepsis, osteomyelitis, UTI, enteritis

1. Young infants younger than 28 days
2. Older infants with temperature >39
3. Immunodeficient children
4. Sickle cell disease
5. Chronic liver/renal/lung/cardiac disease

Question 1

Microbiologic stains?

Answer 1

1. Gram stain
2. Ziehl-Neelson (Acid-fast bacilli)
3. Silver stain (fungi)
4. Wright stain (stool WBCs)

Question 2

Typical pathogen and empiric antibiotics for patient aged less than one month? 1-3 months? Three months to three years? Over three years?

Answer 2

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)

Question 3

When to hospitalize an infant for fever?

Answer 3

1. Less than 28 days old
2. Toxic appearance
3. Meningitis suspected
4. Pneumonia, pyelonephritis, bone/text soft tissue infections which are UNRESPONSIVE to oral antibiotics
5. Uncertain outpatient care and follow up

Question 4

Patient presents with fever – plan if toxic? If nontoxic with fever over 39? Non-toxic with fever under 39?

Answer 4

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

Question 5

Definition of fever of unknown origin?

Answer 5

Fever lasting longer than one to three weeks

Question 6

Laboratory tests for fever of unknown origin?

Answer 6

CBC, ESR/CRP, transaminases, UA/urine culture, blood cultures, ASO titers, AMA/RF, PPD, HIV, stool culture/toxins

Question 7

Bacterial meningitis in children – risk factors? Symptoms?

Answer 7

1. Young age
2. Immunodeficiency (asplenia, humoral immunodeficiency, complement deficiency)
3. 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

Question 8

Bacterial meningitis – LP findings? Other tests? Possible complications? Tx - give what to everyone? Give what else based on age?

Answer 8

1. Lumbar puncture (WBC >5000, glucose ratio under 40%, increased protein, positive Gram stain)
2. Blood culture
3. CT scan with contrast
4. Hearing loss
5. Global brain injury
6. SIADH, nerve palsy, seizures, hydrocephalus

Steroids for all and:

1. Newborns – ampicillin plus aminoglycoside/Ceftriaxone
2. Young infants – ampicillin plus ceftriaxone and vancomycin
3. Older children (greater than three months) ceftriaxone and vancomycin

Question 9

Aseptic meningitis? Causes?

Answer 9

Inflammation of the meninges with lymphocytic pleocytosis, normal glucose, normal CSF protein

1. Viral - enteroviruses, mumps, herpes,
2. Bacterial – TB, Borrelia, treponema
3. Fungal – Coccidioides, Cryptococcus, histoplasmosis
4. Parasitic – taenia, Toxoplasma

Question 10

Diagnosis of viral meningitis? TB meningitis?

Answer 10

Viral culture, PCR, surface cultures from throat/rectum (for enterovirus)

Basilar enhancement on brain imaging, AFB stains, PCR findings

Question 11

Causes of URI? Management? When to evaluate for bacterial superinfection?

Answer 11

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)

Question 12

Development of sinuses?

Answer 12

1. Ethmoid and maxillary sinuses – present at birth (3rd-4th month of gestation)
2. Sphenoid sinuses – 3-5 years
3. Frontal sinuses – 7-10 years

Question 13

Types of sinusitis? – Clinical features?

Answer 13

1. Acute persistent (nasal discharge, cough for 10-30 days, headache, facial pain, fever)
2. Acute severe sinusitis – fever >39 with purulent nasal discharge for 30-90 days
3. Subacute sinusitis – acute persistent sinusitis for 30-90 days
4. Chronic sinusitis – acute persistent sinusitis lasting longer than 90 days

Question 14

Sinusitis – etiology? Management?

Answer 14

for acute persistent, acute severe, subacute:

1. Strep pneumo, H flu, Moraxella
2. Amoxicillin, Augmentin, second-generation cephalosporin

For chronic sinusitis:

1. Underlying condition (cystic fibrosis, allergy, immunodeficiency)
2. Staph aureus plus anaerobes
3. Broad-spectrum antibiotics, CT imaging, IV antibiotics

Question 15

Viral pharyngitis – causes? Clinical features? Management?

Answer 15

1. URI viruses – rhinovirus, parainfluenza, coronavirus, RSV
2. Coxsackie, EBV, CMV
3. URI symptoms
4. Tonsillar exudates
5. If EBV – enlarged posterior cervical lymph nodes and hepatosplenomegaly
6. If Coxsackie – herpangia (painful vesicles on the posterior pharynx) or hand-foot-mouth
7. Analgesics and hydration
8. Severe EBV – corticosteroids

Question 16

Bacterial pharyngitis – causes? Clinical features? Diagnosis? Management?

Answer 16

Streptococcus Pyogenes, group B strep, arcanobacterium, Corynebacterium.

1. 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,
2. 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

Question 17

Acute otitis media – Causes? Clinical features? Diagnosis? Management?

Answer 17

Acute otitis media – infection of middle ear space

Strep pneumonia, nontypeable H. influenzae, Moraxella, viral

1. Fever, ear pain, decreased hearing
2. Develops during/after URI
3. If Tympanic membrane perforates pus draining from ear
4. Diagnosis needs fluid in middle ear (Pneumatic otoscopy) with symptoms of infection (erythema and loss of tympanic membrane landmarks)
5. Tympanocentesis
6. Purulent discharge from external auditory canal
7. amoxicillin
8. If patient attends day care or has received antibiotics within the last two months, use augmentin or cephalosporin

Question 18

Otitis media with effusion?

Answer 18

Fluid within middle ear space without symptoms of infection

Question 19

Otitis Externa – definition? Pathogenesis? Causes? Clinical features? Diagnosis? Management?

Answer 19

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

1. Restore acidity – Acetic acid solution
2. Topical antibiotics
3. If perforated tympanic membrane, add oral antibiotics

Question 20

Cervical lymphadenitis – causes? Clinical Features? Diagnosis? Management?

Answer 20

1. Staph aureus is the most common
2. Strep Pyogenes , Mycobacterium,
3. Bartonella
4. reactive lymphadenitis
5. Viral – EBV, CMV, HIV
6. Kawasaki
7. Toxoplasma
8. Structural (Branchial cleft cyst, cystic hygroma)

Lymph node is mobile, tender, warm, enlarged with erythema

CBC, PPD, anti-body titers, imaging

1. Empiric antibotics, (First-generation cephalosporin or anti-staff penicillin)
2. IV antibiotics for toxic appearing child or child who remains symptomatic

Question 21

Parotitis - causes? Clinical features diagnosis? Diagnosis? Tx? Complications?

Answer 21

1. Bilateral involvement – mumps, CMV, EBV, HIV, influenza
2. Unilateral involvement – staph aureus, strep pyogenes, TB
3. Swelling above angle of jaw and fever
4. Pus from Stensen’s duct
5. CT scan
6. Culture from Stensen’s duct or viral serology (mump’s virus detected in urine)

Supportive care, antibiotics against staph and strep

1. Meningioencephalitis, orchitis, epididymitis, pancreatitis,
2. If bacterial: osteomyelitis of jaw

Question 22

Impetigo – causes? Clinical features? Diagnosis? Management? Complications?

Answer 22

Staph aureus >GABS/strep Pyogenes

Honey colored cresting lesions

Visual inspection (new cultures required)

Oral antibiotics (dicloxacillin, clindamycin)

1. Poststreptococcal GN
2. Staph Scalded skin symptoms

Question 23

Erysipelas – Definition? Cause? Critical features? Diagnosis? Management?

Answer 23

Skin infection involving dermal lymphatics

GABHS

Tender, erythematous skin with distinct border

Visual inspection

Systemic antibiotics against GABHS

Question 24

Cellulitis – definition? Causes? Features? Diagnosis? Management?

Answer 24

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

Question 25

Variations on cellulitis?

Answer 25

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

Question 26

Scarlet fever – cause? Peak incidents? Transmission? Critical features? Diagnosis? Management? Complications?

Answer 26

GABHS; winter/spring; respiratory droplets 1. Prodrome of fever, chills, malaise 2. Exanthem (Begins on trunk, erythematous, sandpaper rash, Pastia's lines (linear petechia), desquamation) Positive throat culture or positive rapid strep test penicillin or macrolides

Question 27

Complications of GABHS infections?

Answer 27

1. Post streptococcal GN – not prevented by antibiotics 2. Poststreptococcal arthritis (not prevented by antibiotics) 3. Dynamic fever (prevented with antibiotics) 4. PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcus) – OCD or to tic disorder after strep infection. Prevented by antibiotics

Question 28

Toxic shock syndrome – causes? Clinical features? Management?

Answer 28

Staph aureus and GABHS, tampons Probable if 5/6, definite if 6/6: 1. Fever over 38.5 2. Hypotension 3. Diffuse macular erythroderma 4. Desquamation 5. Negative blood cultures, CSF, pharynx 6. Multisystem and hopefully including three of: G.I., joints, mucous membranes, sterile pyuria, thrombocytopenia, CNS Antibiotics, IVIG,