Source: Manual of Ambulatory Pediatrics 2010
SOAP Note – Erythema Infectiosum (Fifth Disease)
ERYTHEMA INFECTIOSUM (FIFTH DISEASE)
A mild viral illness that is characterized by a three-stage exanthem. The first is a “slapped-cheek” appearance; the second is a maculopapular rash on the trunk and extremities, which becomes a reticular, lacy rash; and in the third stage, it has periodic evanescence and recrudescence. The disease is of importance primarily because maternal infection during pregnancy can cause spontaneous abortions, stillbirths, and asymptomatic intrauterine infection. This risk, however, is presumed to be only 1% to 2% of those infected.
I. Etiology
A. Human parvovirus B19
B. Referred to as “fifth disease” because it was the fifth childhood exanthem described, the others being measles, rubella, scarlet fever, and roseola.
II. Incidence
A. Community outbreaks are common, most frequently in late winter and in spring.
B. Highest incidence is seen in school-age children between 5 and 15 years of age.
C. More than 60% of adults are immune because of prior disease.
III. Incubation period: 4 to 14 days.
IV. Communicability
A. Transmitted by droplet infection
B. Most infectious prior to onset of rash
C. Secondary spread occurs in about 50% of close contacts
V. Subjective data
A. History of mild systemic symptoms of a nonspecific viral illness which is often identified only in retrospect
1. Low-grade fever
2. Headache
3. Chills
4. Malaise
5. Myalgia
6. Pharyngitis
7. Conjunctivitis
B. Symptoms last for 2 to 3 days and are followed by an asymptomatic period of 4 to 7 days.
C. Rash: Predominantly presenting complaint seen 17 to 18 days after exposure; this is the third stage of the disease.
VI. Objective data: Objective findings vary according to phase of illness.
A. Prodromal phase: Duration, 1 to 4 days; mildly erythematous pharynx or conjunctiva
B. Second stage: Duration, 4 to 7 days; asymptomatic
C. Third stage: Exanthem appears in three stages.
- 1. First stage
a. Typical “slapped-cheek” appearance, which appears 4 to 7 days after resolution of systemic symptoms
b. Fiery red rash on cheeks with circumoral pallor
c. Rash exacerbated by heat - 2. Second stage
a. Appears 1 to 4 days after onset of facial rash
b. Erythematous maculopapular discrete rash on trunk and extremities
c. Fades as central clearing occurs, leaving a lacy, reticulated rash - 3. Third stage
a. 1to 3-week duration
b. Lacy, reticulated rash characterized by periodic evanescence and recrudescence
c. Fluctuations in intensity are associated with environmental changes, such as elevated temperatures and sun exposure.
d. Often pruritic
VII. Assessment
A. Diagnosis is generally easily made by the appearance of the characteristic exanthem. Serology may be done if deemed important to confirm diagnosis.
B. Differential diagnosis: Atypical cases may be confused with other viral exanthems, such as measles, rubella, and enteroviruses, or with drug reactions or other allergic responses.
VIII. Plan
A. There is no specific treatment.
B. Acetaminophen or ibuprofen for associated myalgias
IX. Education
A. Most contagious prior to onset of rash; therefore, isolation or school exclusion is not necessary once rash appears.
B. Avoid contact with pregnant women until the rash begins to fade.
C. Erythema infectiosum contracted during pregnancy can result in spontaneous abortion, stillbirth, and asymptomatic intrauterine infection. Maternal transplacental transmission rate is 33%; fetal death rate is 9%.
D. Fetal abnormalities have not been associated with B19 viral infections during pregnancy.
E. Blood tests to determine diagnosis are generally used only for pregnant women and people who have blood disorders or who are immunocompromised.
F. About 50% to 60% of adults have serologic evidence of past infection.
G. One attack confers immunity.
H. Avoid contact with people with hemolytic anemias.
I. In school-related outbreaks, a 25% attack rate is the norm.
J. Exacerbation of rash can be precipitated by exposure to heat or sun.
K. Rash may recur for weeks to months.
X. Complications: Arthritis is the most common complication, occurring in 80% of adults but in less than 10% of children.
XI. Follow-up: Generally none required
XII. Referral:
A. Children with hypoplastic anemias.
B. Immunocompromised children.