Exanthems Flashcards
Define exanthem
- widespread rash
- usually in children
- toxins, drug, microbes, autoimmune
Three exanthems we will study
- Erythema infectiosum (Fifth disease)
- Hand, Foot, Mouth disease
- measles
Erythema infectiosum
- aka
- causative organism
- timing
- incubation
- transmission
- aka Fifth disease
- caused by Parvovirus B19**
- late winter/early spring
- incubation 4-14 days
- respiratory route, aerosolized droplets
Erythema infectiosum
- clinical findings in children
- MC asx
- nonspecific sx: HA, coryza, low-grade fever
- pharyngitis, malaise, myalgias, diarrhea, nausea, cough, conjunctivitis
- 10% arthralgia or arthritis, lrg joints
Erythema infectiosum
- rash specific clinical findings
- begins with confluent, erythematous, edematous plaques on cheeks “slapped cheek”
- fades 1-4 days
- then pink to erythematous macule or papules on trunk, neck, extensor surfaces
- lesions have central fading = reticulated appearance
- usually no pruritus
- lasts 5-9 days, can recur with triggers (sunlight, exercise, temp change, bath, emotional stress)
Erythema infectiosum
- adult clinical findings
- acute arthropathy is primary finding (MC women)
- symmetric polyarthritis of small joints (hand, knee)
- self-limiting
- can persist/recur for months
- constitutional sx more severe than in children
- Fever, adenopathy, mild arthritis w/o rash most common
- rash if present: reticulated on extremities, rarely slapped cheek
Erythema infectiosum
- dx
- based on clinical findings
- labs usually normal
- IgM anti-HPVB19 antibodies or IgG seroconversion or PCR for B19 DNA possible
Erythema infectiosum
- major complications (2)
- Transient aplastic crisis
- Fetal B19 infection
Erythema infectiosum
- Transient aplastic crisis
- cessation of RBCs
- MC cause in patients with chronic hemolytic anemia
- fatigue, pallor, worsening anemia
Erythema infectiosum
- Fetal B19 infection
- **spontaneous abortion (first half)
- **hydrops fetalis (fluid in compartments like lung or brain)
- late fetal death
- congenital anemia
Erythema infectiosum
- treatment
- none, usually not needed
- supportive therapy for fatigue, malaise, pruritus, arthralgia
- offer serologic B19 testing to pregnant women exposed to B19 (follow with frequent US)
Hand-Foot-and-Mouth Disease
- demographics
- timing
- transmission
- pathogen
- Children <10 MC
- summer and fall
- highly contagious
- oral-oral and fecal-oral
- Coxsackievirus A16 and enterovirus 71
Hand-Foot-and-Mouth Disease
- clinical findings
- first: low-grade fever, malaise, abd pain, URI sx
- nearly all: painful oral lesions on tongue, buccal mucosa, hard palate
- later: 2/3 get cutaneous lesions on hand, feet, buttocks (occasionally genitalia, face, legs)
- red macule and papules > vesicle with red halo > crust/erosion
Hand-Foot-and-Mouth Disease
- diagnosis
- clinical dx
- no labs
Hand-Foot-and-Mouth Disease
- tx
self-limiting in 7-10 days
- supportive tx only
Hand-Foot-and-Mouth Disease
- complication
- aseptic meningitis
Measles
- aka
- transmission
- timing
- rubeola
- highly contagious, respiratory droplets
- contagious several days before onset of rash and up to 5 days after lesions appear
- winter and spring
- Immunization greatly reduces incidence
Measles
- clinical presentation
prodrome
- high fever, malaise, conjunctivitis, coryza, cough. May last up to 4 days
Exanthem:
- 4th febrile day
- erythematous, non-pruritic macs/paps on forehead at hairline and behind ears
- spreads centrifugally and inferiorly to face, trunk, extremities, palms/soles
- reaches feet by day 3
- resolves in 4-6 days
Measles
- Enanthem
- cluster of tiny bluish-white spots on red background
- **Koplik spots: on buccal mucosa opposite premolar teeth
- on or after second day of febrile illness
Measles
- other sx
- vomiting
- diarrhea
- abd pain
- splenomegaly
- pharyngitis
- otitis media
- generalized lymphadenopathy
Measles
- dx
Clinical suspicion, confirm via serology:
- MC: measles-specific IgM antibody and measles RNA via PCR
- obtain both serum sample and throat swab
- higher prob of detection if collect respiratory and urine samples
Measles
- complications
- MC <5 yo and >20 yo
- **pneumonia (MC in children)
- otitis media
- laryngotracheobronchitis
- diarrhea
- acute encephalitis (perm brain damage)
- subacute sclerosing panencephalitis - rare but fatal, can develop 7-10 years after measles infection
measles
- tx
- primarily supportive
- maintain good hydration
- transmission precautions for 4 days after rash onset
- tx secondary bacterial infections with abx
- Severe case tx with vitamin A (dz can lead to vitamin A deficiency)
- People exposed should receive prophylactic immunoglobulin prophylaxis within 6 days of exposure
