INFECTIOUS DISEASES Flashcards
Multiple erythematous macules and petechiae on palms and soles of a patient with headache and malaise
What is the infectious condition?
Rocky Mountain spotted fever (RMSF)
What is the electrolyte abnormality associated with RMSF?
Hyponatremia
Abrupt onset of fever, chills, malaise, then with ulcerated skin lesion and tender regional lymph node
What is the infectious agent?
Franciscella tularensis
Retroauricular, posterior cervical, and posterior occipital lymphadenopathy in an unvaccinated patient
What is the diagnosis?
Rubella (aka German measles)
What is the unique oral finding in rubella?
Reddish-pink spots on soft palate
Rashes involving the axilla, groin, antecubital areas in patients with fever.
What is the diagnosis? Causal organism?
Scarlet fever
Caused by group A strep
Treatment of E.coli O157:H7 (Shiga-toxin producing)
Supportive care with fluid and electrolyte management
Toddler with weeks of progressive hoarseness, recurring wheezing, found to have stridor.
What is the diagnosis? Causal organism?
Juvenile laryngeal papillomatosis
Caused by HPV type 6 or 11
What are the causal organism and XR finding of juvenile laryngeal papillomatosis?
Caused by HPV type 6 or 11
XR finding: soft tissue lesion at the level of vocal cords
First line in pertussis-exposure prophylaxis
Azithromycin
(second line = Bactrim for age > 2 months)
Treatment of Salmonella diarrhea
Supportive care - NO antibiotics (unless patient has hemoglobinopathies, immunocompromised, or critically ill)
Stridor, throat pain, difficulty swallowing - XR shows a prominent prevertebral soft tissue swelling displacing the trachea forward
What is the condition? The most common causal organism?
Retropharyngeal abscess
Most common = Group A Strep (Strep pyogenes)
Treatment for suspected meningitis in neonate < 7 days
Ampicillin + Cefotaxime
Which organism children with persistent complement component deficiency are at risk for ?
Neisseria meningitidis
Treatment of cat-scratch disease
Azithromycin
What are main side effects of isonazid ? (3)
1 - Hepatitis / elevated LFTs
2 - Peripheral neuritis
3 - Hypersensitivity
What are main side effects of rifampin? (2)
1 - Discoloration of urine (orange)
2 - Render oral contraceptives ineffective
Most common complication of mumps in males?
Epididymo-orchitis
- acute onset of fever and severe testicular pain from swelling and erythema of scrotum
Mouth infection with beaded, branching chains of gram-positive rods and “sulfur” granules
What is the organism?
Actinomyces
Chronic draining lesions after water exposure
What is the organism?
Mycobacterium marinum
Perceptual distortions and lymphadenopathy
What is the syndrome? What is the causal organism?
Alice-in-Wonderland syndrome
Part of infectious mononucleosis (EBV)
XR of a young child with indolent back pain shows disc space narrowing and irregularity of the vertebral end plates.
What is the condition? What is the most common organism causing this?
Discitis
Most commonly caused by Staph aureus
Who should received prophylaxis for meningococcal exposures?
Individuals with close contacts WITHIN 7 days prior to onset of disease
Most common cause of swimming-related conjunctivitis
Adenovirus
Most common cause of bacterial conjunctivitis
Strep pneumo
Erythematous rash eruption over face and trunk 3-5 days after fever, child is otherwise well
What is the most likely diagnosis? Organism?
Roseola
HHV-6 or HHV-7
Persistent lymphadenitis, not improving despite appropriate cephalexin and/or clindamycin.
What is the most likely organism?
Mycobacterium avium-intracellulae
Unique lab finding associated with Chlamydia trachomatis infection in children?
Eosinophilia
Behavioral changes + involvement of temporal lobe on MRI
What is the diagnosis?
Herpes meningoencephalitis
First line treatment for UTI children > 2mo who is relatively well, no allergies
Cephalexin
(first-generation cephalosporin)
First line treatment for UTI children > 2mo who is relatively well, allergic to penicillin
Ciprofloxacin
Suboccipital lymphadenopathy and morbilliform rash in a patient with conjunctivitis
What is the diagnosis?
Rubella
Non-purulent conjunctivitis, posterior cervical lymphadenopathy, otitis media
What is the organism?
Haemophilus influenzae
Conjunctivitis, exudative pharyngitis, vesiculopapular rash
What is the condition?
Herpangina / Hand-foot-mouth
Non-purulent conjunctivitis, exudative pharyngitis, preauricular lymphadenopathy
What is the organism?
Adenovirus
Acute peripheral facial neuropathy and an erythematous vesicular lesions in ear canal
What is the diagnosis? What is the causal organism? Treatment?
Ramsay-Hunt syndrome
VZV
Acyclovir + steroids
Animal exposure, swollen ulcerative lesion with associated eschar formation
What is the diagnosis? Treatment?
Tularemia
Gentamicin (or streptomycin)
Animal exposure, swollen ulcerative lesion with associated eschar formation
What is the diagnosis? Treatment?
Tularemia
Gentamicin (or streptomycin)
Infant with eosinophilia and a cough
What is going on?
Chlamydia trachomatis infection
Generalized, confluent, erythematous, finely papular rash especially in groin and axilla.
What is the organism?
Group A strep
What is first line treatment for Lyme arthritis?
Doxycycline x 28 days
What are skin findings in cat-scratch disease (Bartonella)
Several cutaneous papules/pustules develop at the inoculation site.
Bluish-white papules covering the buccal mucosa
What is this finding ? What is the underlying agent?
Koplik spots
Measles
Swelling of joints and a reticular rash
Which virus causes this ?
Parvovirus B19
Prophylaxis for close contacts of individuals with invasive meningococcal disease
Rifampin x 2 days
What is the organism caursing discitis?
What is the blood cutulre finding ? WBC ? ESR/CRP?
Staph aureus
Usually negative blood culture
Usually NORMAL WBC
Elevated inflammatory markers ESR/CRP
Painful, grouped, deep-seated vesicles with clear fluid on erythematous base on finger.
What is the diagnosis? What is the organism? Treatment?
Herpetic whitlow
HSV-1
Oral acyclovir
Neonate with microcephaly, hydrocephalus, microphthalmia, chorioretinitis, generalized cerebral calcifications
What is the congenital infection?
generalized cerebral calcification = Toxoplasma gondii
(CMV presents with periventricular intracranial calcifications)
Neonate with microcephaly, hydrocephalus, microphthalmia, chorioretinitis, periventricular intracranial calcification
What is the congenital infection?
periventricular intracranial calcification = CMV
(generalized calcification = Toxoplasma)
Neonate born with severe limb malformations and microphthalmia
What is the congenital infection?
Varicella embryopathy
Neonate born with smooth philtrum, thin upper limp, small palpebral fissures, and growth restrictions, microcephaly
What is going on?
Fetal alcohol syndrome
Sandpaper-like rash
What is the condition? Causal organism?
Scarlet fever
Group A strep pharyngitis
Multiple grouped vesicles and ulcers involving the tongue and buccal mucosa with gingival erythema
What is the condition? Causal organism?
Herpetic gingivostomatitis
HSV
What is CBC finding commonly seen in pertussis?
Lymphocytosis
What are the 3Cs of measle?
Cough, coryza, conjunctivitis
What is the post-exposure prophylaxis for children exposed to measles?
MMR vaccine within 72 hours
Spiral- or helical-shaped gram negative organism that causes bacterial diarrhea
What is the organism? What is the treatment?
Campylobacter jejuni
Macrolides (azithromycin)
What are long-term complications of Campylobacter jejuni infections? (2)
Reactive arthritis
Guillain-Barre syndrome
Decolonization therapy for community-acquired MRSA carriers
Topical mupirocin to anterior nares twice daily x 5 days
Blue-berry muffin rash in a neonate
What is the diagnosis? What is the most common cardiac anomaly?
Congenital rubella syndrome
Patent ductus arteriosus (PDA)
Gram-positive diphtheroid-like organism in blood culture
What is the organism? What is the first line treatment?
Listeria
Penicillin or ampicillin
(NOT vancomycin)
Gram-negative diplococci grew from CSF culture
What is the organism? The patient should be screen for which condition?
Neisseria meningitides
(meningococcal)
screen for terminal complement component deficiecy (check CH50)
Sharply definied, slightly elevated, distinct border skin rash
What is the organism?
Group A Strep
(Strep pyogenes)
What are the criteria for diagnosing acute bacterial sinusitis ? (At least 1 of 3)
1 - Persistent nasal discharge of any quality or daytime cough with no improvement > 10 days
2 - Worsening symptoms AFTER initial improvement of typical viral URI that lasted 5-6 days (“double sickening”)
3 - Fever > 102 F ( >39 C) with either purulent nasal discharge or facial pain for >3 consecutive days in an ill-appeariung child
Penetrating eye injury with ring abscess formation in the cornea
What is the possible organisms? (3)
Ring abscess:
1 - Bacillus cereus
2 - Pseudomonas
3 - Proteus
Eye infection due to direct contact lenses, or swimming with contact lenses
What is the organism?
Acanthamoeba
Most common etiology of brain abscess in infant?
Citrobacter
(gram-negative rod)
Most common location of adenitis in non-tuberculosis mycobacterial disease (NTM)
Submandibular
What are 2 organisms causing pneumonia in patients with recent influenza?
1 - Streptococcus pneumoniae
2 - Staphylococcus aureus
Otitis externa in patient with diabetes
What is the treatment to cover for which specific organism?
Ciprofloxacin PO
to cover for Pseudomonas
Most common cause of aseptic meningitis in children?
Enterovirus
How to distinguish enterovirus from HSV CNS infection in children?
HSV usually causes meningoencephalitis, not just isolated meningitis. Looks for mental status change
Unilateral non-purulent conjunctivitis with an ipsilateral preauricular lymphadenitis
What is the organism? What is treatment?
Bartonella henselae
(this is an atypical presentation of catscratch disease)
Treatment = azithromycin
Neonate with chorioretinitis/conjunctivitis, microcephaly, and skin vesicles / scarring
What is the congenital infection?
HSV
Bloody or serosanguinous vaginal discharge / vulvovaginitis
What are the most common agents? (2)
1 - Shigella
2 - Group A Strep
Changes with breastfeeding if mom has mastitis?
No change! Continue breastfeeding from both breasts
Which pathogen can cause invasive disease in patients who receive cochlear implant
Strep pneumoniae
Growth restriction, hearing loss associated with developmental delay, cataract, and cardiac findings in a newborn
What is the congenital infection?
Congenital rubella syndrome
Frontal bossing, saddle nose, interstitial keratitis, hearing loss, intellectual disabilities
What is the congenital infection?
Congenital syphilis
(Treponema pallidum)
Most common cause of subacute bacterial endocarditis?
Viridan strep
Most common cause of acute bacterial endocarditis?
Staph aureus
Osteomyelitis of the calcaneus
What is the most likely organism?
Pseudomonas
(after a nail puncture)
What is the first line treatment of pertussis?
What is a potential complication of this treatment in young infant?
Macrolides
In young infant, might cause infantile hypertrophic pyloric stenosis
(azithro has less risk than erythro - therefore better choice)
What is the first line treatment of pertussis?
What is a potential complication of this treatment in young infant?
Macrolides
In young infant, might cause infantile hypertrophic pyloric stenosis
(azithro has less risk than erythro - therefore better choice)
Most common cause of congenital sensorineural hearing loss in infants
CMV
What is eye finding frequently seen with roseola?
Palpebral and periorbital edema
(NOT bulbar conjunctivitis - which should raise concern for Kawasaki)
What is the common eye finding in bacterial endocarditis?
Conjunctival and retinal hemorrhages
Non-blanching, linear, brownish-reddish lesions located beneath nail bed
What is the finding called? Underlying condition?
Splinter hemorrhages
Bacterial endocarditis
Tender, pea-sized, intradermal nodules located within the pads of fingers / toes
What is the finding called? Underlying condition?
Osler nodes
Bacterial endocarditis
Erythematous papules on foot, with brownish-red, well-demarcated serpiginous plaques extend from each papule
What is the disease? What is the source? Treatment?
Cutaneous larva migrans
- the larval stages of dog/cat hookworms
treat with oral albendazole
Non-purulent conjunctivitis with an associated enlarged preauricular lymph node, with biopsy showing necrotizing granuloma.
What is the diagnosis? Causal organism?
Parinaud oculoglandular syndrome
Innoculation of Bartonella henselae into / around the eye
Non-purulent conjunctivitis with an associated enlarged preauricular lymph node, with biopsy showing necrotizing granuloma.
What is the diagnosis? Causal organism?
Parinaud oculoglandular syndrome
Innoculation of Bartonella henselae into / around the eye
Maternal infections that are contraindications for breastfeeding in the US ? (4)
1 - HIV
2 - HTLV-1
3 - HTLV-2
4 - untreated TB
Which children should get renal & bladder ultrasound after 1st UTI ? (3)
1 - Children < 2 years
2 - those with hypertension or failure to thrive
3 - not responding to initial therapy
What are clinical signs and symptoms of toxic shock syndrome (TSS) ? (5)
What is the causing organism?
1 - Fever
2 - Hypotension
3 - Altered mental status
4 - Intensely erythematous generalized rash (erythroderma)
5 - Mucous membrane inflammation
Caused by S.aureus toxin
Treatment of Rocky Mountain spotted fever?
Doxycycline
Lethargy, vomiting after taking aspirin.
What is going on?
Reye syndrome
What is the first line treatment for enterococcus?
Ampicillin
(2nd line = vanco)
(tends to resistant to cephalosporins of all generations!)
Management of cat-scratch disease in immunocompetent patients?
Can confirm diagnosis with serology, then observe
1st line of therapy for cat-scratch disease in immunocompromised patient?
Azithromycin
What is the measles postexposure prophylaxis for infants < 6-month-old ?
IVIG (or IMIG) within 6 days of exposure
What is the measles postexposure prophylaxis for infants 6-month-old to 11 month-old ?
MMR vaccine within 72 hours (or IVIG within 6 days of exposure)
(MMRV vaccine is not for < 12 month old)
Which medication to absolutely avoid in patient with chicken pox?
Aspirin (can cause Reye syndrome)
What is the prophylaxis for meningococcal exposure? (include correct dose)
Rifampin 10 mg/kg/dose x 2 days
What is the prophylaxis for Hib exposure? (include correct dose)
Rifampin 10 mg/kg/dose x 4 days
Management of children < 5 years old who are exposed to TB ? (2 steps)
1 - Start therapy for LTBI (“window prophylaxis”) until TB screening is negative
2 - Get a CXR
How long to wait to place PPD or send IGRA after MMR vaccine? Why?
4-6 weeks after
because measles vaccine may temporarily suppress TB screening reactivity
Treatment of chlamydial conjunctivitis in neonate?
Erythromycin or azithromycin
XR findings of osteochondritis or periostitis in an infant
What is the congenital infection?
Congenital syphillis
Tetanus prevention:
Wound is dirty and either (1) < 3 immunizations or (2) unknown immunization
Tetanus immunoglobulin + vaccine
Tetanus prevention:
Wound is clean and immunization up-to-date (>=3 shots, <10 years since last)
No treatment
(if > 10 years since last, give vaccine only)
Tetanus prevention:
Wound is dirty and immunization up-to-date (>=3 shots, <5 years since last)
No treatment
(if > 5 years since last, give vaccine only)
Symmetric, erythematous swelling of hands and feed, sharply dermacated at the wrists and ankles - with painful papules or petechiae
What is the condition? What is causal organism?
Papular purpuric gloves and socks syndrome (PPGSS)
Parvovirus B19
Diarrhea after uncooked hot dogs and goat chesse
What is the most likely organism?
Listeria
What is the most common cause of neonatal breast abscess?
Staph aureus
Infant presents with sudden onset of irritability, poor feeding, and unilateral facial swelling, with postauricular lymphadenopathy.
What is the condition? What is the causal organism? Treatment?
Cellulitis-adenitis syndrome
caused by Group B Strep (Strep agalactiae)
Empiric therapy with amp + gent + vanc
Giemsa stain of a patient with asplenia who has fever
What is the diagnosis?
Babesiosis (casued by Babesia)
(Maltese cross sign)
Spreading pattern of rash in scarlet fever
“Sand-paper” rash starts chest/neck -> trunk/extremities
Spreading pattern of rash in measles
Hairline -> downward/outward
Spreading pattern of rubella
Face->downward
Spreading pattern of Rocky Mountain spotted fever
Flexor surfaces of ankles/wrists -> palms/soles -> inward
What is the most common long-term sequela of acute bacterial meningitis ?
Hearing loss
“Strawberry tongue” associated with which diseases? (2)
1 - Scarlett fever
2 - Kawasaki disease
Erythematous tonsils with membrane formation and petechiae at the junction of the hard & soft palate
What is the causal mechanism?
EBV
What are 3 ways that neonatal HSV can present?
1 - Skin, eye, mucous membrane (SEM)
2 - Disseminated infection
3 - CNS-limited infection
How to differential Chlamydia vs Gonorrhea ophthalmia neonatorum in neonate?
Onset
Onset of N.gonorrhea conjunctivitis usually 2-5 days of delivery, Chlamydia 5 - 12 days
Malaria prophylaxis for areas known to be resistant to chloroquine
Doxycycline
Empiric antibiotics treatment for acute epiglotitis
Ceftriaxone + Vancomycin
What are the two most common causes of osteomyelitis in sickle cell disease (2, in right order)
1 - Staph aureus
2 - Salmonella species
