Infectious Flashcards by Denisse Tiangco

Caused by HHV6
Peak at 6-9m
95% of children have been infected by 2 mos

Saliva transmission from entry to oral nasal or conjunctivs

Supress cellular lineages in bone marrow

Fever in first 3-5 days and rash

Exanthem subitum
Roseola
Sixth disease

How well did you know this?

Not at all

Perfectly

Most conmon type of roseola

Type B

How well did you know this?

Not at all

Perfectly

Fever in 3-5d with fusiness 90%
Rash in 12-24 h of fever resolution

Asians: ulcer in uvulopalatoglossal junction called

Nagayama spot

Roseola

How well did you know this?

Not at all

Perfectly

Where is the koplik spot best appreciated

Opposite lower molar

How well did you know this?

Not at all

Perfectly

RNA virus from paramyxoviridae by droplet aerosol in prodromal period

Incubation 8-12 d

Period of comm is 4 days before and 4 days after onset of rash

Measles

How well did you know this?

Not at all

Perfectly

Causes necrosis of respi epithelium
Small vessel vasculitis in skin and mucous membrane

Pathognomonic of
(multinucleated giant cells)

Measles

Warthin Finkeyldey giant cells

How well did you know this?

Not at all

Perfectly

High grade fever with conjunctivitis and colds 3-5 d

Measles prodrome

How well did you know this?

Not at all

Perfectly

Enanthem Grayish white dot with red border opposite lower molar 1-4d prior onset of rash

Rash at height of fever

Koplik spots

How well did you know this?

Not at all

Perfectly

Rash fades downward in same seq which it appears

Rash: cephalocaudal with branny desquamation in 7-10d

Measles

How well did you know this?

Not at all

Perfectly

Rash in Roseola

starts at trunk and then grows peripheral

How well did you know this?

Not at all

Perfectly

Give to prevent complications in measles

Vitamin A: single 100,000 IU for 6-1 yr
200,000 IU for >1
OD x 2 d
<6 mos: 50,000 IU

If with vit A def, repeat after 1 month

How well did you know this?

Not at all

Perfectly

Measles complication

Otitis media
Pneumonia
SSPE

How well did you know this?

Not at all

Perfectly

Delayed chronic complication due to persistent infection with virus

SSPE

How well did you know this?

Not at all

Perfectly

Ulcers in uveopalatoglossal junction

Nagayama spot

Sixth disease

How well did you know this?

Not at all

Perfectly

Painful enlargement of parotid glands as usual presenting sign

by RNA virus of paramyxoviridae

Period of comm: 1-2 d before onset of parotid swelling till 5 days after onset of swelling

Respiratory droplet

Mumps

How well did you know this?

Not at all

Perfectly

Pain and swelling of one or both parotids (1-3d)
Fills the space bet posterior border of mandible and mastoid
Pushes earlobe upward and outward and angle of mandible no longer seen
Swelling subsides in 7d
Edema of homolateral pharynx and soft palate displacing tonsil medially
Edema of larynx and manubrium

Mumps

How well did you know this?

Not at all

Perfectly

Most freq complication of mumps

Meninggoencephalitis in 5 days

Others
Orchitis and epididymitis (infertility rare)
Oophoritis
Dacryoadenitis
Optic neuritis

How well did you know this?

Not at all

Perfectly

3 day measles
Caused by RNA from Togaviridae
Spreads by oral droplet of transplacental to fetus
Risk for congenital defects and disease greatest with primary maternal infection during 1st tri

Period of comm: 5d before until 6d after onset of rash

Rubella

German measles

How well did you know this?

Not at all

Perfectly

Most prominent Characteristic of rubella

Retroauricular
Posterior cervical
Postoccipital LAD (24h before rash till 1 week)

How well did you know this?

Not at all

Perfectly

enanthem in Rubella

discrete rose spots on soft palate

Forscheimer spots

How well did you know this?

Not at all

Perfectly

Rubella in older girls present with

Polyarthritis

No photophobia

How well did you know this?

Not at all

Perfectly

Pertussis is causes by

Bordetella pertussis Gram neg

How well did you know this?

Not at all

Perfectly

Secretion from RT of infected person

Transmission by close contact with large aerosol drops

Pertussis

Whooping cough

How well did you know this?

Not at all

Perfectly

Most infectious stage of pertussis/whooping cough

Catarrhal stage

How well did you know this?

Not at all

Perfectly

Stages of Pertussis | 3 lasting 2 weeks each stage

Catarrhal Paroxysmal -explosive outbursts of cough in 5-10 series in one expiration and ending in high pitched whoop associated with suffusion of face, popping out of eyes and vomiting Convalescent

In between paroxysms of pertussis,

child may look well | conjunctival or petechial hemorrhage on upper body

Tx for pertussis

Erythromycin 40-50 mg/kg/day q6 PO or IV Placed in respiratory isolation for at least 5 days after initiation of antibiotics Beyond this nininfectious

Results in lifelong latent infection of sensory ganglion neuron

Primary Chickenpox

Caused by neurotropic human herpes virus Transmission: oropharyngeal secretion by airborne spread and direct contact Period of comm: 1-2d before onset of rash till 3-7d after rash until ALL has crusted

Varicella

Rash pattern in varicella

Starts on scalp, face or trunk with rapid progression | Simultaneous presence of lesions in various stages

Varicella complications

``` Secondary bacterial infection Meninggoencephalitis Pneumonia Reye syndrome GN ```

Fetus infected at 6-12w of gestation with max interruption with limb development (short and malformed) covered with: which are skin lesions with zigzag scarring assoc eith atrophy of affected limb

Congenital varicella cicatrix

If infected at 16-20w of gestation, varicella may induce

eye and brain involvement in fetus

Lifetime risk for herpes zoster

10-15% with 75% of cases occuring after 45yrs

Due to Parvovirus B19 Transmission by large droplet spread and blood Rash and aplastic crisis in 5-15 y o

Erythema infectiosum | 5th disease

Parvo B19 target

erythroid cell with arrest in development of RBCs

Erythema infectiosum hallmark sign

Slapped cheek: rash erythematous facial flushing | spreads rapidly to trunk prox extremities and diffuse macular edema

Lacy reticulated appearance of rash on extremities esp on extensor areas Palms and soles spared Rash resolves without desquamation waxes and wanes in 1-3 weeks Not infectious at presentation bec rash and arthropathy are immune mediated

Erythema infectiosum

Virus replication from Flaviviridae carried by Aedes egypti Viremua Ag-ab complex Complement cascade and Hagemab factor activation Extravasation of fluid Shock

Dengue

Dengue fever rash:

Transient macular generalized rash blanching under pressure seen during first 24-48h of fever

Generalized maculipapular rash appearing which spares the palms and soles and disappears in 1-5 days with desquamation

Hermann’s rash

Day 1-4 illness dx of dengue

Dengue NS1

End of acute phase dengue dx

Serology IgM by day 5 IgG low titer at end of first week of illness even after several months If secondary infection IgG first week to 10 mos

``` Dengue endemic area with fever + any 2 of ff: headache myalgia Arthralgia Retroorbital pain Body malaise Nausea and vomiting Anorexia diarrhea flushed skin And ``` CBC with leukopenia with or without thrombocytopenia

Probable dengue

Dengue endemic + fever lastinf 2-7d plus any one Abdominal pain Mucosal bleed Persistent vomiting Lethargy, restlessness Liver enlargement Dec or no urine output within 6h Labs: inc in hct and dec platelet count

With no warning But if with liver enlarge: with warning

Dengue endemic + fever in 2-7d + dengue with or without warning signs plus any one:

``` Shock Fluid accumulation with respiratory distress Liver AST or ALT >1000 CNS: seizure, impaired consciousness Heart: myocarditis Kidneys: renal failure ``` Severe Dengue

``` Fever Dehydration Normal Hct Normal platelet High viral load: NS1 (viremia) ```

Febrile phase

``` Afebrile Shock Bleeding Organ impairment DECREASED HCT DECREASED PLATELET COUNT ``` IgM +

Critical Dengue phase

Reabsorption Fluid overload Platelet IgM/IgG

Recovery Dengue phase

Recovery phase in dengue is characterized by

Diuresis | Monitor UO

Caused by Corynebacterium Transmission: direct contact via airborne respiratory droplet Period of communicability: variable

Diptheria

``` Organism in superficial layers of skin Produce exotoxin Inhibits protein synthesis and causes necrosis Gray grown adherent pseudomembrane May cause paralysis of palate Bukl neck appearance Leather like adherent membrane ```

Diptheria

Diptheria vs strep

Lack of fever | Non exudative throat

Diptheria dx

Culture from nose and throat from beneath membrane including the membrane Negative results do not rule out

Diptheria tx

Pen G IM/IV 100,000 - 150,000 U/kg/day q6 for 14 d Erythromycin 40-50mg/kg/day if allergic also to eradicate nasopharyngeal microbe

Asymptomatic case contact of diptheria pxs

Benzathine Pen G 600,000 U IM for younger 6 1.2M IM for 6 yrs Or Erythromycin 40-50mg/kg/day for 10d

Complication of diptheria:

Toxic cardiomyopathy | Toxic neuropathy

Most common complication of mumps

Meningoencephalitis

Most common complication of congenital rubella syndrome

sensorineural hearing loss

Most debillitating complication of shingles

neuropathic pain

Most common dermatome involved in shingles

Thoracic | Lumbar

DOC for neuropathic pain

pregabalin | gabapentin

Pregabalin and gabalin binds to

Alpha 2 delta subunit of voltage gated channel (a2d)

Only FDA approved for trigeminal neuralgia

Carbamazepine

FDA approved for DM neuropathy

duloxetene Level A: Pregabalin

HLA in chinese that predilects risk for SJS

HLA B1502

Most common drugs causing SJS

Sulfonamide Phenytoin, Phenobarb, CBZ Allopurinol

Preferred tx for pertussis

Azithromycin

Infant <1 With pyloric stenosis: palpable olive Hx of cardiac problem (QT) Avoid

macrolide

Ingestion of food or water contaminated by S typhi Period of comm: throughout excretion in feces

Typhoid fever

``` High grade fever Gen myalgia Abdominal pain Hepatosplenomegaly Rose spots in 25% lower chest and abdomen ```

Typhoid fever

Complications of typhoid

Intestinal hemorrhage | Intestinal perforation

Typhoid fever dx

Blood culture - 1st week of illness Urine Stool - after 1st week

Typhoid fever tx

Uncomplicated and sensitive: Chloramphenicol 50-75mg/kg/day Amoxicillin x 14d

Excretion of S typhi for more than 3 | mos

Chronic carrier

Aerobic nonspore forming | Coagulase +

Staph aureus

Staph coag neg

Epidermidis Saprophyticus Hemolyticus

Secondary to exfoliative toxin A&B Rash preceded by malaise, fever, irritability, exquisite skin

Staph scalded skin syndrome

Secondary to enterotoxin Severe nausea, vomiting, abd pain, watery diarrhea

Staph food poisoning

Necrotizing pneumonia Pneumatocoele Pleural effusion Empyema

Staph pneumonia

Major cause of bacterial pharygitis Petechisl mottling of soft palate

Group A Beta hemolytic strep

Dx of strep pharyngitis

throat culture | serology

DOC for strep pharygitis

Penicillin V <60 lbs 250 2-3x/day >60 lbs 500 2-3x/day 10 days, start before first 10 days of treatment prevent RHF Erythromycin 10d if allergic

Causes by pyrogenjc exotoxin or erythrogenic toxin | Fever, vomiting; toxicity

Scarlet fever

scarlet fever rash

gooseflesh or sandpaper rash

Erythematous indurated with advancing margins with raised firm borders

Erysipelas

Rheumatic fever | GN

both by GAS

Sudden OCD Tic disorder Autoimmune antibody in response to GAS crossreacting with brain tissue

PANDAS

In children most common valves affected in RHD are

Mitral valve | Aortic valve

Most common symptom in polyarthritis responds to

Polyarthritis ASA

Diagnosis of RF can be made without following guidelines if presence of the ff

Chorea Indolent carditis Recurrent RF

toxin for splitting of skin by SSS

exfoliatin a, b

toxin for pneumatocoele

panton valentin leukocidin

Responsible for golden yellow colonies or pigment of staph

Staphyloxanthin

Most severe form of SSS

Ritters disease

Parenchymal lung pattern of Pseudomonas

Fleur de lis pattern

Striking whitish necrotic center

Fleur de lis pattern of pseudomonas

Rash in scarlet fever

boiled lobster appearance