Presentation. The disease usually presents with a febrile episode, progressing to nasal congestion and malaise. One to 2 days later, the classic rash appears. Patients with HFMD usually present with papular or vesicular lesions on the hands and feet and painful oral lesions (FIGURES 4A, 4B, and 4C). The rash may also affect other parts of the body including the legs and buttocks. Desquamation of nails may occur up to one month after the HFM infection.27 Most cases are diagnosed by clinical presentation, but infection can be confirmed by PCR of vesicular lesion fluid.
Complications. In addition to being caused by Coxsackievirus, HFMD may be caused by human Enterovirus A serotype 71 (HEVA-71), which is associated with a high prevalence of acute neurologic disease including aseptic meningitis, poliomyelitis-like paralysis, and encephalitis.26 Of 764 HFMD patients enrolled in a prospective study, 214 cases were associated with Coxsackievirus A 16 (CVA16) infection and 173 cases were associated with HEVA-71 infection. Rare cases of HFMD have led to encephalitis, meningitis, flaccid paralysis, and death.26
Treatment and prevention. HFMD is usually self-limited, and treatment is supportive. There has been interest in developing an HFMD vaccine, but no products are as yet commercially available.
Rubella
Rubella, also known as the German measles or the 3-day measles, is caused by the rubella virus, which is transmitted via respiratory droplets. Up to half of rubella infections are asymptomatic.28-30
Presentation. Rubella typically has an incubation period of 12 to 24 days, with a 5-day prodromal period characterized by fever, headache, and other symptoms typical of an upper respiratory infection, including sore throat, arthralgia, and tender lymphadenopathy.28
The rash often starts as erythematous or as rose-pink macules on the face that progress down the body. The rash can cover the trunk and extremities within 24 hours. (For photos, see https://www.cdc.gov/rubella/about/photos.html.)
Patients are infectious from 7 days prior to the appearance of the rash to 7 days after resolution of the rash. Given the potentially prolonged infectious period, patients hospitalized for rubella infection should be placed on droplet precautions, and children should be kept from day care and school for 7 days after the appearance of the rash.28
Rubella is typically a mild disease in immunocompetent patients; however, immunocompromised patients may develop pneumonia, coagulopathies, or neurologic sequelae including encephalitis.
Complications. Rubella infection, especially during the first trimester, can lead to spontaneous abortion, stillbirth, or congenital rubella syndrome (CRS), a condition characterized by congenital cataracts and “blueberry muffin” skin lesions.31 Infants affected by CRS can also have heart defects, intellectual disabilities, deafness, and low birth weight. Diagnosis of primary maternal infection should be made with serologic tests. Fetal infection can be determined by detection of fetal serum IgM after 22 to 24 weeks of gestation or with viral culture of amniotic fluid.31
Treatment and prevention. Currently, no antiviral treatments are available; however, vaccines are highly effective at preventing infection. Rubella vaccine is usually given as part of the measles, mumps, rubella (MMR) vaccine, which is administered at age 12 to 15 months and again between 4 and 6 years of age.
Measles
Measles is a highly contagious disease caused by a virus that belongs to the Morbillivirus genus of the family Paramyxoviridae. Infection occurs through inhalation of, or direct contact with, respiratory droplets from infected people.32
Presentation. People with measles often present with what starts as a macular rash on the face that then spreads downward to the neck, trunk, and extremities (for photos, see http://www.cdc.gov/measles/hcp/index.html). As the disease progresses, papules can develop and the lesions may coalesce.
The rash is often preceded by 3 to 4 days of malaise and fever (temperature often greater than 104° F), along with the classic symptom triad of cough, coryza, and conjunctivitis. Koplik spots—clustered white lesions on the buccal mucosa—are often present prior to the measles rash and are pathognomonic for measles infection.33
Because the symptoms of measles are easily confused with other viral infections, suspected cases of measles should be confirmed via IgG and IgM antibody tests, by reverse transcription-PCR, or both.34,35 For limited and unusual cases, the Centers for Disease Control and Prevention can perform a plaque reduction neutralization assay.35
Complications. Measles infection is self-limited in immunocompetent patients. The most common complications are diarrhea and ear infections, but more serious complications, such as pneumonia, hearing loss, and encephalitis, can occur. Children <2 years of age, particularly boys, are at an increased risk of developing subacute sclerosing panencephalitis, a fatal neurologic disorder that can develop years after the initial measles infection.33,36
Treatment and prevention. Treatment is supportive and usually consists of acetaminophen or NSAIDs and fluids.
A live attenuated version of the measles vaccine is highly effective against the measles virus and has greatly reduced the number of measles cases globally.37 The measles vaccine is usually given in 2 doses—the first one after one year of age, and the second one before entering kindergarten. The most common adverse reactions to the vaccine are pain at the injection site and fever. Despite the fact that the MMR vaccine is effective and relatively benign, measles outbreaks continue to occur, as some parents forego routine childhood immunizations because of religious or other personal beliefs or safety concerns.38