Pediatric Viral Exanthems
Faculty: Jonathan Dyer, MD
Dr. Dyer began his afternoon lecture on pediatric viral exanthems discussing measles. Most health care providers are aware of the recent increase in measles cases in the US. Of note, there is currently a major outbreak of measles in Africa that has killed over 5000 people. Dr. Dyer reports measles is “one of the most contagious diseases known”. The measles virus can live up to two hours in airspace where an infected person has coughed or sneezed. Presentation of the rhinoconjuctivitis associated with measles tends to be quite dramatic. Additionally, Dr. Dyer reports measles is very immunosuppressive increasing patients’ risk for secondary bacterial infections. In regards to reactions to the measles mumps rubella vaccine (MMR), measles is the main active factor that can cause rash and fever. Mumps is another viral exanthem on the rise in the US. Most of the cases have been in patients > 20 years of age. Of note, up to 20% of patients with mumps are completely asymptomatic. Patients who have mumps are infectious for 2 days prior to symptoms and up to 5 days after onset. The main concern for mumps is the high rate of 20-50% orchitis in post pubertal males. Additionally, up to 15% of patients who present with mumps will have CNS involvement.
The measles virus can live up to two hours in airspace where an infected person has coughed or sneezed.
Next, Dr. Dyer illuminated Coxsackie A 6 virus or “a cousin” of the typical hand foot and mouth disease. He reports these patients present with intense vesicular eruptions. This virus strain is very onychotropic with high rates of nail shedding. The viral exanthem of Coxsackie A6 virus tends to be more widespread than standard hand foot and mouth disease. Of note, as this is a different strain of Coxsackie, adults may not have immunity and their presentation tends to be more severe, sometimes requiring hospitalization. Fifth disease, or Parvovirus B19, was illustrated with the typical “slapped cheek” presentation which is more common in younger children. Dr. Dyer reports the lacy reticular rash of erythema infectiosum can last for 1-3 weeks and it is important to inform parents the rash tends to go through cycles where it “fades” and then presents again. He also reports fifth disease is a major cause of petechial rash in children.
Dr. Dyer reports that Coxsackie A 6 patients present with intense vesicular eruptions.
Dr. Dyer went on to discuss serum sickness reaction, or urticaria multiforme, which is often misdiagnosed as erythema multiforme. This rash tends to be “striking” though children who present with this condition do not tend to present as very sick. Children with urticaria multiforme do complain of joint pain and will present with swelling in their joints. Fortunately, this is short lived and is not an arthritis. Serum sickness reaction can occur with and without preceding drug exposure, rather drug exposure may potentiate the reaction. Additional conditions Dr. Dyer touched upon include an id reaction of molluscum contagiosum, orf and papular purpuric gloves and socks syndrome.