Infections characterized by fever and rash Flashcards
What are Koplik spots?
- gray-white, sand grain sized dots on the buccal mucosa opposite the lower molars
- Pathognomonic of measles
What causes the measles?
Measles virus
- Single stranded RNA virus
What are the four phases of measles infection?
1) Incubation (8-12 days)
2) Prodrome (3 days) CCCPK
- Cough
- Conjunctivitis
- Coryza (inflammed mucosa in the nose)
- Photophobia
- Koplik spots
- Often High fever (over 40)
3) Exanthematous rash
4) Recovery
- Macular rash begins above hairline and speads caudally over most of body
What is the treatment for measles?
Supportive care
- Hydration
- Antipyretics
- Vitamin A supplementation x 2 days
What is the most common cause of death in a patient with the measles?
- Bronchopneumonia
- Encephalitis
- Late deaths due to panencephalitis (immune encephalitis 8-10 years after infection)
In Ontario when are children vaccinated for measles?
- 12 months of age with MMR vaccine
- Between 4 and 6 with MMRV vaccine
What are contraindications to the measles vaccine?
- Immunocomprimised
- Immunosuppressive dose of corticosteroids
- Pregnancy
German measles or 3-day measles is another name for what?
- Rubella
- What causes Rubella?
- Rubella virus
- Single stranded RNA virus
How are measles spread? When is someone contagious?
- Highly contagious
- Transmitted by droplets or by airborne route
- Infectious period is 1-2 days before symptoms until the rash has been present for 4-5 days
- Boot camp says 5d before and 4d after rash IMPORTANT
How is rubella spread? When is someone contagious?
- Most contagious through direct or droplet contact with nasopharyngeal secretions
- Contagious from 7 days before until 14 days after the appearance of rash (most from 2 days before to 5-7 days after)
What is congenital rubella syndrome?
Refers to the variable constellation of birth defects associated with intrauterine rubella infection
- Including: Hearing impairment, growth restriction congenital heart defects, cataracts, congenital cataracts, pigmentary retinopathy and more
What is the incubation period for post natal rubella?
14-21 days (2-3 weeks)
What are the clinical manifestations of rubella?
1) Lymphadenopathy
- RETROAURICULAR and PREAURICULAR
- posterior cervical
- posterior occipital
2) Maculopapular rash
- Begins on face
- Spreads to body
- Lasts 3 DAY RASH
- Less prominant than measles rash
3) Forchheimer spots
- 20% of pts
4) Other
- Mild pharyngitis
- Conjunctivitis
- Anorexia
- Low grade fever
- Polyarthritis of hand
What are forchheimer spots?
- Small petechiae of the soft palate
- Occur in 20% of rubella cases
- Typically occur before rash
How is rubella managed?
Supportive therapy
- hydration
- Antipyretics
When are vaccines against rubella given in Ontario?
- 12 months MMR
- between 4-6 MMRV
What is roseola infantum also known as? What causes it?
- 6th disease or Exanthem subitum
- Caused by human herpes virus type 6
- Double stranded DNA virus
What are the clinical features of roseola infantum?
- High fever (often >40)
- Abrupt onset
- Lasts 3-5 days
- Macrulopapular rose coloured rash that begins as fever subsides typically (may occur earlier)
- Rash typically lasting 1-3 days
- Febrile seizures
- URTI symptoms
What is the treatment for roseola infantum?
- Supportive care (fluids, antipyretics)
- In immunocompromised hosts ganciclovir or foscarnet can be used
What is erythema infectiosum also called? What causes it?
- Fifth disease (slap cheek)
- Parvovirus B19
- Single stranded DNA virus
What are the clinical manifestations of of erythema infectiosum?
1) Begins as mild non-specific illness
- fever
- malaise
- myalgia
- headache
2) Rash in 3 stages (7-10 days after prodrome)
a) slapped cheek rash
b) erythematous symmetric maculopapular rash 1-4 days later
c) lacy, reticulated rash that lasts 2-40 days (mean 11)
What can parvovirus B19 do to red blood cells?
- Virus can bind to erythrocyte progenitor cells preventing them from developing
- Only significant in those with shortened RBC lifespan (hemolytic anemias such as sickle cell, spherocytosis, thalassemia)
- If this occurs they may develop a transient aplastic crisis lasting 7-10 days
- Very low retics, low HgB
What is the treatment for erythema infectiosum?
- Supportive care (hydrate, antipyretic)
- Transfusions may be needed for aplasic crisis
Infection with parvovirus B19 during pregnancy is associated with a risk of what to the fetus?
- Fetal death
- Hydrops fetalis
What causes the chicken pox?
- Varicella-zoster virus
- Double stranded DNA virus
When is chicken pox contagious?
- 2 days before the onset of rash until the lesions are crusted over (typically 7 days)
How is varicella zoster virus transmitted?
- Direct contact
- Droplet
- Air
What are the clinical features of varicella?
1) generally occurs 14-16 days after exposure
2) Prodrome (1 day prior to rash)
- fever
- malaise
- anorexia
3) Rash
- small red paupule that progress to nonumbilicated oval vesicles on erythematous base
- Marked puritis
4) Healing
- Fluid from clear to cloudy
- Vesicles ulcerate, crust and heal
Describe the rash seen in varicella
- Small red paupule that progress to nonumbilicated oval vesicles on erythematous base
After resolution of varicella, the virus persists in latent form where?
- Dorsal root ganglia cells
- Reactivation of the varicella virus causes what?
- Herpes zoster (shingles)
intense localized pain alone a dermatome with an eruption of pupules that quickly vesiculate is most likey caused by what?
- Zoster (Shingles)
A zoster infection to which nerve may cause corneal and intraoral lesions?
Cranial Nerve V
What is ramsay hunt syndrome? What triad is associated with it?
1) Zoster affecting cranial nerve VII
- Other cranial nerves may be involved as well
2)
a. Ipsilateral facial paralysis
b. ear pain
c. vesicles in auditory canal and auricle
When would you consider treating a patient with varicella with valacyclovir (or similar)? Why?
1) Those at risk of severe varicella
- Immunocompromised
- unvaccinated person over age 12
- Chronic cutaneous or pulmonary disease requiring steroids
- Long term salicylate use (^ risk of reye syndrome)
2) Treated to prevent severe complications:
- Pnemonia
- Encephalitis
- Death
* Note dose of antivirals higher with varicella than with zoster
Why is varicella screened for in pregnancy?
- A severe form of neonatal varicella may develop in newborns of mothers with varicella (not shingles) occuring 5 days before to 2 days after delivery
- Fetus is exposed to large amount of the the virus but is born before maternal antibody response develops and can cross placenta
What type of vaccine is the varicella vaccine? When is it given in Ontario?
- Live attenuated
- Given at 15 months as single varicella vaccine
- Second dose between 4 and 6 years part of combined MMRV
What is kowasaki disease?
- A vasculitis of unknown etiology that is characterized by multisystem involvement and inflammation of medium-sized arteries with resulting aneurysm formation
For kowasaki disease:
a) Which age group is affected?
b) Which ethnic group is most affected
a) Children under 5 years (peaks between 2 and 3)
b) Highest frequency in Japan
What are you most worried about in a child with kowasaki disease?
- Coronary artery aneurysm
What are the 3 phases of kowasaki disease? explain them
1) Acute phase (1-2 weeks)
- sudden onset high fever (>40) w/o source
- conjunctival erythema
- mucosal changes (dry cracked lips, STRAWBERRY TONGUE)
- cervical lymphadenopathy
- Swelling of hands and feet
- Rash in 80% most often inguinal region and chest
2) Subacute phase (weeks 3 and 4)
- Gradual resolution of fever
- Desquamation of skin
- Thrombophilia
- Coronary artery aneurysm
3) Convalescent phase
- Begins with disappearance of clinical signs and continues until ESR normalizes
- Beau lines of fingernails may appear (horizontal grooves in nail)
Describe how you would work up a suspected case of kowasaki disease?
1) Rule out other causes of fever
- blood and urine culture
- CXR
- consider lumbar puncture
2) Inflammatory markers
- CRP, ESR, WBC
3) Evaluate for coronary artery aneurysm with echo
- In acute phase
- repeat at 2-3 weeks
- repeat again at 6-8 weeks
What are the diagnostic criteria for kowasaki disease?
1) Presence of fever for more than 5 days without identified source
2) 4+/5 of:
a) bilateral conjunctivitis (no pus)
b) oral mucous membrane changes
- 1+ of:
- pharyngeal injection
- dry fissured lips
- injected lips
- strawberry tongue
c) 1+ changes to extremities
- peripheral erythema
- peripheral edema
- periungual desquamation (fingers or toes)
- general desquamation
d) Cervical lymphadenopathy >1.5cm
e) disease not explained by other known disease process
How is kowasaki disease managed?
1) Intravenous immunoglobulin (IVIG)
- single dose (2g/kg) over 12hr
2) ASA
- anti-inflammatory dose during acute phase (80-100mg/kg/day) divided q6h
- After acute phase 3-5mg/kg/day until final echocardiogram f/u at 6-8 weeks
3) Echo
- during acute phase
- again at 2-3 wks
- again at 6-8 wks
Kowasaki disease is one of the only instances in which ASA is used in children. Why is ASA usually not used? What do you do to lower this risk?
- Risk of reye syndrome
- Give child influenza vaccine in lower the risk
When is erythema infectiosum contagious?
- Starting 5-10 days after exposure.
- Contagious period lasts 5 days
Kowasaki disease is also called what?
Mucocutaneous lymph node syndrome
