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Flashcards in Exanthems Deck (23)
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1
Q

Define exanthem

A
  • widespread rash
  • usually in children
  • toxins, drug, microbes, autoimmune
2
Q

Three exanthems we will study

A
  • Erythema infectiosum (Fifth disease)
  • Hand, Foot, Mouth disease
  • measles
3
Q

Erythema infectiosum

  • aka
  • causative organism
  • timing
  • incubation
  • transmission
A
  • aka Fifth disease
  • caused by Parvovirus B19**
  • late winter/early spring
  • incubation 4-14 days
  • respiratory route, aerosolized droplets
4
Q

Erythema infectiosum

- clinical findings in children

A
  • MC asx
  • nonspecific sx: HA, coryza, low-grade fever
  • pharyngitis, malaise, myalgias, diarrhea, nausea, cough, conjunctivitis
  • 10% arthralgia or arthritis, lrg joints
5
Q

Erythema infectiosum

- rash specific clinical findings

A
  • 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)
6
Q

Erythema infectiosum

- adult clinical findings

A
  • 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
7
Q

Erythema infectiosum

- dx

A
  • based on clinical findings
  • labs usually normal
  • IgM anti-HPVB19 antibodies or IgG seroconversion or PCR for B19 DNA possible
8
Q

Erythema infectiosum

- major complications (2)

A
  • Transient aplastic crisis

- Fetal B19 infection

9
Q

Erythema infectiosum

- Transient aplastic crisis

A
  • cessation of RBCs
  • MC cause in patients with chronic hemolytic anemia
  • fatigue, pallor, worsening anemia
10
Q

Erythema infectiosum

- Fetal B19 infection

A
  • **spontaneous abortion (first half)
  • **hydrops fetalis (fluid in compartments like lung or brain)
  • late fetal death
  • congenital anemia
11
Q

Erythema infectiosum

- treatment

A
  • 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)
12
Q

Hand-Foot-and-Mouth Disease

  • demographics
  • timing
  • transmission
  • pathogen
A
  • Children <10 MC
  • summer and fall
  • highly contagious
  • oral-oral and fecal-oral
  • Coxsackievirus A16 and enterovirus 71
13
Q

Hand-Foot-and-Mouth Disease

- clinical findings

A
  • 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
14
Q

Hand-Foot-and-Mouth Disease

- diagnosis

A
  • clinical dx

- no labs

15
Q

Hand-Foot-and-Mouth Disease

- tx

A

self-limiting in 7-10 days

- supportive tx only

16
Q

Hand-Foot-and-Mouth Disease

- complication

A
  • aseptic meningitis
17
Q

Measles

  • aka
  • transmission
  • timing
A
  • 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
18
Q

Measles

- clinical presentation

A

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

19
Q

Measles

- Enanthem

A
  • 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
20
Q

Measles

- other sx

A
  • vomiting
  • diarrhea
  • abd pain
  • splenomegaly
  • pharyngitis
  • otitis media
  • generalized lymphadenopathy
21
Q

Measles

- dx

A

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
22
Q

Measles

- complications

A
  • 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
23
Q

measles

- tx

A
  • 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