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Erythema Infectiosum, Emergency Medicine

Basics

Description

- "Slapped-cheek" appearance most common in young children - Fever - Malaise - Delayed symptoms 4-14 days later: - Diffuse, pruritic, lacy rash (absent in most adults), most pronounced in extremities - Symmetric polyarthropathy, most common in middle-aged women: - Small joints involved in adolescents and adults - Knees most commonly involved in children - Secondary to immune-complex deposition

- No specific antiviral treatment or vaccine is available - Send appropriate labs (CBC, reticulocytes, antibody testing) for severe cases - Symptomatic treatment as needed: - IVF for severe dehydration - NSAIDs for arthropathy if no underlying renal insufficiency - Consider diphenhydramine for pruritus, caution parents about possible AMS - Antipyretics for fever

- Association with papular, purpuric gloves, and socks syndrome in adults: - Symmetric, painful progressive rash and edema of hands and feet - Erythema progresses to petechiae, purpura, and occasionally bullae - This syndrome is also associated with many other viruses and drugs

  • Characteristic viral exanthem also known as 5th disease:5th most common childhood rash historically describedMeasles (1st), scarlet fever (2nd), rubella (3rd), Duke disease (4th), roseola (6th)
  • Common symptoms: Viral prodrome followed by slapped-cheek rash and subsequent diffuse reticular rash +/- arthropathy
  • Most common in school-aged children <14 yr
  • Usually self-limited with lasting immunity
  • Rare complications and chronic cases in patients with congenital anemias or immunosuppression
  • Potential for severe complications to fetus if infection acquired during pregnancy
  • Possible link to encephalopathy, epilepsy, meningitis, myocarditis, dilated cardiomyopathy, autoimmune hepatitis, HSP, ITP

Etiology

  • Caused by human parvovirus B19, small SS-DNA virus:Infects human erythroid progenitor cells, suppressing erythropoiesis
  • Most common in late winter and spring
  • Transmitted via respiratory droplets and blood products as well as vertical maternal-fetal transmission
  • Incubation period 4-21 days
  • Most contagious during the week PRIOR to rash onset
  • Majority of adults have serologic evidence of prior infection

Diagnosis

Signs and Symptoms

  • "Slapped-cheek" appearance most common in young children
  • Fever
  • Malaise
  • Delayed symptoms 4-14 days later:Diffuse, pruritic, lacy rash (absent in most adults), most pronounced in extremitiesSymmetric polyarthropathy, most common in middle-aged women:Small joints involved in adolescents and adultsKnees most commonly involved in childrenSecondary to immune-complex deposition
  • However, most patients remain asymptomatic or only develop mild, nonspecific viral symptoms

History

  • Mild constitutional symptoms (fever, headache, nasal congestion, nausea, sore throat)
  • Contagious only until facial rash appears

Physical Exam

  • Stage 1:"Slapped-cheek" rash of coalescent, warm, erythematous, edematous papules with circumoral pallor in young children
  • Stage 2:Nonspecific, diffuse, pruritic, maculopapular, reticular eruption4-21 days after facial rash, lasts up to 6 wkMore prominent on extremitiesUsually spares palms and soles
  • Stage 3:Rash fades but recurs with exposure to sunlight, stress, exercise, and heat
  • Usually complete resolution without scarring

Essential Workup

Clinical diagnosis based on characteristic signs and symptoms.

Diagnosis Tests & Interpretation

  • Usually not necessary
  • CBC and reticulocyte count if concern for aplastic crisis
  • Confirm diagnosis if immunocompromised or pregnant:Viral DNA PCR now availableIgM antibody confirms acute infection and persists for 2-3 moIgG presence confers lasting immunity
  • In pregnancy, ultrasound to detect hydrops fetalis

Differential Diagnosis

  • Allergic reaction
  • Collagen vascular disease
  • Coxsackie virus
  • Drug eruptions
  • Enterovirus
  • Erysipelas
  • Infectious mononucleosis
  • Measles
  • Nonspecific viral illness
  • Rheumatoid arthritis
  • Roseola
  • Rubella
  • Scarlet fever
  • Sunburn

Treatment

Erythema infectiosum is usually self-limited and does not require treatment

Pre-Hospital

ABCs for severe cases and septic patients

Initial Stabilization/Therapy

  • ABCs, supplemental oxygen if indicated
  • IVF with associated severe dehydration
  • Severe anemia may also cause hypotension and hypoxia, transfuse PRBCs as indicated
  • Pain control with acetaminophen, NSAIDs, or opiates as needed for severe arthropathy

Ed Treatment/Procedures

  • No specific antiviral treatment or vaccine is available
  • Send appropriate labs (CBC, reticulocytes, antibody testing) for severe cases
  • Symptomatic treatment as needed:IVF for severe dehydrationNSAIDs for arthropathy if no underlying renal insufficiencyConsider diphenhydramine for pruritus, caution parents about possible AMSAntipyretics for fever
  • PRBC transfusion for severe anemia
  • ID consult: IVIG may have benefit for immunocompromised patients with chronic symptoms and red cell aplasia
  • Hematology consult for severe cases
  • Hospitalization and respiratory isolation for aplastic crisis

Medication

  • Acetaminophen: 500 mg (peds: 15 mg/kg/dose) PO q6h PRN fever for up to 5 daysDose not to exceed 4 g/24h
  • Diphenhydramine: 25 mg (peds: 1-2 mg/kg/dose) PO q6h PRN itching for up to 5 days
  • Ibuprofen: 400 mg (peds: 10 mg/kg/dose) PO q8h PRN pain for up to 5 days
  • IVIG only in consultation with ID specialist

Follow-Up

Disposition

Admission Criteria

  • Aplastic crisis or severe anemia
  • Severely immunocompromised
  • Hydrops fetalis
  • Toxic appearance
  • Severe arthritis

Discharge Criteria

  • Nearly all patients
  • Normal CBC, O2 sat, and BP
  • Patients are no longer contagious following appearance of facial rash and may return to day care, school, or work

Issues for Referral

  • All patients without existing primary care physicians should be referred to a generalist for follow-up as needed
  • Patients with hereditary anemias should be referred to hematology for follow-up in 1-2 days
  • All immunocompromised patients require prompt subspecialty follow-up
  • Pregnant patients with new infection should have immediate follow-up with OB/GYN for further monitoring and ultrasound

Follow-Up Recommendations

  • Pregnant women with new parvovirus B19 infection may need serial ultrasounds for 10-12 wk.
  • Patients at risk for aplastic crisis should follow-up with the appropriate specialties 1-2 days after ED discharge for repeat CBC

Patient Education

Prevention:

  • No vaccine available
  • Frequent handwashing helps prevent spread
  • No current recommendations to keep children out of school, since most children are no longer contagious by the time the diagnosis is made.
  • Pregnant women may choose to stay away from a workplace outbreak, but no current official recommendation exists

Complications

  • Transient aplastic crisis in patients with anemias: Sickle cell disease, hereditary spherocytosis, thalassemia, iron-deficiency, or other conditions with shortened red cell lifespan:Usually full recovery within 2 wk
  • Persistent infection with severe anemia if immunocompromised and unable to mount antibody response, especially with HIV
  • Arthritis or hypersensitivity dermatitis in adults:May have transient rheumatoid factor positivity, but no true association with rheumatoid arthritis and no joint destruction
  • Association with papular, purpuric gloves, and socks syndrome in adults:Symmetric, painful progressive rash and edema of hands and feetErythema progresses to petechiae, purpura, and occasionally bullaeThis syndrome is also associated with many other viruses and drugs
  • Extremely rare - hepatosplenomegaly, heart failure, CVA, thrombocytopenia, leukopenia
  • Risk of hydrops fetalis in pregnancy
  • 60% of pregnant women are susceptible to new infection
  • 30% risk of transplacental infection with new maternal infection
  • Affects fetal liver (main site of erythropoiesis), leading to anemia, CHF, myocarditis, IUGR
  • 2-6% risk of fetal loss, highest in 2nd trimester

Pearls and Pitfalls

  • Parvovirus B19 is usually a self-limited, mild illness.
  • Common symptoms include "slapped-cheeks" rash with subsequent diffuse lacy rash and arthropathy
  • Patients are no longer contagious when the rash appears and aplastic crisis resolves
  • Evaluate all patients with history of hereditary or iron-deficiency anemia for aplastic crisis
  • Evaluate all patients with history of immunosuppression for chronic infection with persistent anemia
  • Confirm diagnosis in all pregnant patients. If no proven immunity, monitor for fetal complications and refer for follow-up

Additional Reading

  • Servey JT, Reamy BV, Hodge J. Clinical presentations of parvovirus B19 infection. Am Fam Physician. 2007;75:373-376.
  • Vafaie J, Schwartz RA. Erythema infectiosum. J Cutan Med Surg. 2005;9:159-161.
  • Weir E. Parvovirus B19 infection: Fifth disease and more. CMAJ. 2005;172:743.

Codes

ICD9

057.0 Erythema infectiosum (fifth disease)

ICD10

B08.3 Erythema infectiosum [fifth disease]

SNOMED

  • 34730008 erythema infectiosum (disorder)