Childhood Exanthems

by Robin R. Hemphill, MD

• Measles (Rubeola):
  Measles is a contagious viral infection characterized by fever, cough, conjunctivitis, and coryza. There is significant morbidity and mortality associated with this disease.
  • Incubation Period: 10-12 days
  • Usual Age of Onset: Infants - Young Adults
  • Mode of Transmission: Respiratory droplets
  • Infective period: from start of prodrome until day 5 of exanthem
    • Prodrome: Typical measles: 3 - 4 days of coryza, conjunctivitis,photophobia, malaise cough, & high fever. Atypical measles: 2-5 days of high fever, myalgias, & cough.
    • Exanthem: Typical measles: Erythematous macules & papules starts behind ears & at scalp margin (usually on the fourth febrile day) then spread to entire body reaching the feet by the third day. Brown pigmentation during resolution. Atypical measles: Papular or papulovesicular & often hemorrhagic. Start on extremities & spread central.
    • Enanthem: Koplick spots - appear before exanthem & fade within 2-3 days of rash. These are small bluish-white papules which appear on the buccal mucosa.
  • Complications and Associated Findings:
    • Usually, a self-limited disease.
    • Otitis media, generalized lymphadenopathy, bronchopneumonia (bacterial or measles), meningitis, encephalitis, toxic appearance, photophobia may occur.
    • Atypical measles: virtually always a lobular or segmental pneumonia.
    • Chronic complication: subacute sclerosing panencephalitis
  • DDX: Atypical measles, rubella, scarlet fever, roseola, 5th disease, drug eruption, secondary syphilis, mononucleosis.
  • Treatment:
    • Prevention via prophylactic immunization
    • Oral Vitamin A 400,OOOU for severe measles
    • Administration of appropriate antibiotics for secondary bacterial infections
  • Lab/ Dx: Clinical, acute/conv hemaglutinin inhibition (HAI) serology
  • Agent: Paramyxovirus (RNA virus)
  Measles Photo
• Scarlet Fever:
  Scarlet fever is an infection of the skin and/or tonsils by an exotoxin-producing strain of group A streptococcus.
  • Incubation Period: 1-4 days
  • Usual Age of Onset: childhood
  • Mode of Transmission: Respiratory droplets or fomites
  • Infective period: Contagious early in infection
    • Prodrome: 1-3 days of sore throat, fever, myalgias, vomiting, and abdominal pain.
    • Exanthem: Starts 1-3 days after onset of the fever. Begins as a erythematous (sunburn appearance) rash on the trunk which has a "sandpaper" feeling when palpated. Perioral pallor is present. Patia's lines are linear petechiae which occur in the skin folds. The exanthem fades after 4-5 days and is followed by desquamation.
    • Enanthem: Beefy red pharynx and tonsils. Petechiae on the palate. White to red "strawberry tongue.
  • Complications and Associated Findings:
    • Nonsuppurative sequelae: rheumatic fever, acute glomerulonephritis
    • Streptococcal toxic shock syndrome
  • DDX: Drug reaction, Staph as cause
  • Treatment: Penicillin or Erythromycin
  • Lab/ Dx: Throat culture, rising ASO titer
  • Agent: Group A beta-hemolytic streptococci
• Rubella:
  Rubella is a childhood infection that is manifested by a characteristic rash. In childhood it usually runs a benign course. However, in pregnant women infection may cause significant congenital abnormalities.
  • Incubation Period: 14-21 days
  • Usual Age of Onset: adolescents/ young adults
  • Mode of Transmission: Respiratory droplets
  • Infective period: 7 days before and 5 days after rash
    • Prodrome: 1-7 days of malaise, tender post-auricular and occipital adenopathy
    • Exanthem: Well defined rose-pink macules and papules which begin on the face and move caudally. Typically the rash resolves within three days. The rash is less confluent than measles.
    • Enanthem: Petechiae or reddish macules on the soft palate.
  • Complications and Associated Findings:
    • There are minimal constitutional symptoms in the pediatric population.
    • Arthritis and arthralgias are more common in adults, particularly women.
    • Severe fetal complications may occur if infection develop in first half of pregnancy (cataracts, coronary disease, deafness, etc).
  • DDX: Other viral exanthems and drug eruptions
  • Treatment:
    • no specific therapy
    • prophylaxis by immunization
  • Lab/ Dx: Rubella IgM or acute/convalescent IgG titers
  • Agent: Rubella virus
• Erythema Infectiosum (Fifth's Disease):
  • Incubation Period: 4-14 days
  • Usual Age of Onset: 5-15 days
  • Mode of Transmission: Respiratory Droplets
  • Infective period: During prodrome and 7 days after onset of symptoms. Not during rash.
    • Prodrome: 1-4 days of mild fever, headache, chills. Patients may be asymptomatic.
    • Exanthem: Bright red "slapped cheeks" followed later by reticulated macules and papules most prominent on the extremities. This rash may wax and wane over the next 7-14 days.
    • Enanthem: None
  • Complications and Associated Findings:
    • Transient arthritis and arthralgias especially in adults.
    • Transient aplastic crisis
    • Intrauterine infection and fetal death may occur rarely
  • DDX: Other viral exanthems
  • Treatment: None specific
  • Lab/ Dx: Diagnosis is usually clinical, however, IgM assays can be done.
  • Agent: Parvovirus B19
• Roseola Infantum(Exanthem Subitum):
  • Incubation Period: 7-15 days
  • Usual Age of Onset: 6 months-three years
  • Mode of Transmission: Unknown
  • Infective period: During illness
    • Prodrome: High fever for three to five days. Child may appear ill.
    • Exanthem: Well defined erythematous blanching macules, distributed on the neck, trunk, and buttocks. Rash lasts 2-34 hours and typically appears after the fever breaks.
    • Enanthem: Erythematous macules and streaks on the soft palate, 48 hours prior to exanthem.
  • Complications and Associated Findings:
    • Cervical and postauricular adenopathy, mild coryza, cough, headache.
    • Complications are rare, but febrile seizures may occur
  • DDX: Other exanthems such as enterovirus, adenovirus, rubella, EBV
  • Treatment: None specific
  • Lab/ Dx: Diagnosis is made clinically
  • Agent: Human Herpes Virus
• Chicken Pox (Varicella):
  This is a contagious infection that is characterized by pruritic vesicles which develop into pustules, crusts, and potentially, scars. Infections in adulthood may run a more complicated course.
  • Incubation Period: 10-21 days
  • Mode of Transmission: Respiratory Droplets, and uncommonly, direct contact with herpes zoster.
  • Usual Age of Onset: 1-14 years
  • Infective period: Several days prior to vesicles, until all lesions are crusted.
    • Prodrome: Low grade fever and malaise
    • Exanthem: Macules and papules that become vesicles on an erythematous base ("dew drop on a rose pedal")The rash may start on the face and spreads to the trunk and extremities.
    • Enanthem: Ulcers on the palate
  • Complications and Associated Findings:
    • Course is usually benign in the pediatric population
    • Secondary infection of the vesicles
    • Varicella pneumonia is common in adult population
    • Varicella encephalitis
    • Infections in the first-trimester of pregnancy may result in congenital malformations
  • DDX: Enteroviruses, generalized herpes infection, bullous form of impetigo
  • Treatment:
    • Avoid salicylates
    • In healthy patient's symptomatic therapy for pruritus is usually adequate
    • Treat infected vesicles
    • Acyclovir may be considered in early adult infections
    • Hospitalization and IV acyclovir for severe varicella, varicella pneumonitis, varicella infection in immunocompromised host.
    • Varicella-zoster immune globulin may be considered in nonimmune immunocompromised patients
  • Lab/ Dx: Usually a clinical diagnosis. Tzank preparation may be done or viral culture
  • Agent: Varicella-Zoster Virus

MEASLES PHOTO

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POX PHOTO