Exanthema in children

Exanthema is a medical term that denotes a diffuse rash, characterized by:

Usually, the rash is accompanied by systemic symptoms, such as:

Usually it is provoked by a contagious viral disease.
The rash may be caused by a drug (especially antibiotics and anti-inflammatories), for example, lichenoid exanthema.

This rash often affects children, but it can also occur in adults.


What are the causes of exanthema?

During childhood, exanthema is very common and is mainly caused by the following viral infections:
1. seasonal flu, including respiratory diseases or gastrointestinal diseases;
2. chickenpox (cause pustules and blisters on the trunk of the body, face, arms and legs);
3. Measles;
4. Rubella;
5. viral hepatitis;
6. rubella (erythema infectiosum);
7. Three-day fever or roseola infantum (exanthema subitum).
8. other infection with adenovirus, Coxsacki, etc.

The rash can also be caused by bacteria or other infectious diseases, which include:
1. Mycoplasma pneumonia;
2. Kawasaki syndrome;
3. rickettsia;
4. smallpox (now hopefully eradicated by vaccination);
5. infectious mononucleosis;
6. scarlet fever (begins in the groin and under the armpits, and then spreads to the face, trunk and joints);
7. Meningococcal disease;
8. Lyme disease (due to tick bite);
9. Staphylococcal infection,
10. Toxic shock syndrome (TSS) caused by staphylococci;
11. Streptococcal Induced Toxic Shock Syndrome (STSS);
12. Toxic newborn erythema may occur in newborns, which are absolutely benign red spots.

Signs and symptoms of exanthema

Most of the non-specific rashes appear as dots or spots, they occur with or without itching.
Usually, the rash is diffuse and can spread to:

  • Trunk
  • Extremities.

In most cases, and even before a rash is seen, general symptoms may occur, such as:

1. Fever
2. malaise
3. Headache
4. Loss
of appetite 5. Abdominal pain
6. Irritability
7. Muscle pain
These signs and symptoms may vary depending on the cause of the rash.
Virus-related rashes often cause small epidemics and the children infect each other.

Urticaria-like rash

Urticaria-like rash is a rash consisting of itchy and raised spots that appear anywhere and can be provoked by an allergic reaction.
This type of skin reaction is called urticaria (hives).

Macular or maculopapular rash


  • Measles virus is an RNA virus in the family of paramyxoviruses (genus Morbillivirus).
  • Measles has an incubation period of 10-12 days.
  • The disease begins with:
  • The Koplik spots are white or gray papules on the oral mucosa, which can be detected at the end of the prodromal phase (period of incubation, before the appearance of the rash).
  • About 3-4 days after the prodromal symptoms, the typical exanthema stage appears with:
  • At the beginning, they show:
    • behind the ears,
    • in the area of the hairline.
  • Later, they spread over the rest of the skin for a few days. The rash then usually goes back as it has presented, the skin often cracks (scaling).
  • There is currently no specific antiviral therapy for measles, the treatment is symptomatic.
  • More important is the long-term availability of a measles vaccine that makes the disease manageable.


  • Rubella (or German measles) is caused by an RNA virus from the toga virus family.
  • About 40-50% of those infected become symptomatic, the remaining 50-60% have no symptoms.
    After an incubation period of 2-3 weeks, symptomatic patients show prodromal signs, such as:

  • The rash appears after about 2-5 days and spreads from the head to the feet.
  • The rash is macular or maculopapular with non-confluent (non-overlapping) spots of 2-3 mm in size.
  • Symmetrical lymphadenopathy (swollen lymph nodes) is characteristic of rubella (it does not occur in the other exanthemic diseases) and usually manifests itself:
    • behind the ears,
    • at the back of the head.
  • Rubella is contagious one week before the rash appears until 4 days after it subsides.
  • If rubella occurs during pregnancy, damage can occur to the unborn child, including:
  • Doctors recommend that girls and women get vaccinated against this disease.

Erythema infectiosum (rubella)

Erythema infectiosum (rubella) is a common eczematous infantile disease caused by the Parvor virus B19, which belongs to the family of parvoviruses.
The name B19 derives from the identification number used to label the sample of positive serum in which the virus was found.
It is the only parvovirus directly linked to a human disease.
Although parvovirus can manifest itself in various ways, erythema infectiosum is the most common.

Rubella manifests itself in three overlapping phases.

  • At the first stage, after an incubation period of 1-2 weeks, patients show:
    • fever,
    • flu symptoms (malaise, headache),
    • bright red butterfly erythema on the face.
      For this reason, erythema infectiosum is also referred to as “slap disease”.
  • At the second stage, 1-4 days after cheek erythema, patients develop:
    • macula-like or garland-shaped erythema,
    • Joint pain.
  • In the third phase (re-acute symptoms), the rash occurs intermittently, in response to stimuli, for example:
    • local stimuli,
    • high temperatures,
    • emotional stress.

Three-day fever (exanthema infantum)

  • The three-day fever (exanthema infantum) is caused by a human herpes virus (HHV-6, rarely HHV-7), which is very present in the healthy population and is latent in macrophages and T-lymphocytes.
  • The viruses are contained in the saliva of healthy people, the reactivated pathogenic potential of the virus varies from asymptomatic infection to serious diseases in transplant recipients.
  • Within the first two years of life, about 90% of children are seropositive (have antibodies) for HHV-6.
  • It is a typical disease for children from 6 months to 2 years.
  • HHV-7 infection usually occurs later, from the age of 3 onwards in about 65% of infected children.

How long does it take?
After an incubation period of 5-15 days, children infected with three-day fever develop a high fever that lasts for 3-5 days.
This is followed by the appearance of an acute pinkish rash, which does not cause itching and spreads to the neck and trunk area.
Due to the high fever, patients often fall ill with an occult bacterial infection.

Epstein-Barr virus

  • The Epstein-Barr virus (EBV) is a pathogen that belongs to the family of herpes viruses, which also causes mononucleosis.
  • Only about 5-10% of children infected with EBV develop a rash.
  • Doctors may prescribe antibiotics to treat streptococcal infection, which usually occurs along with mononucleosis; however, when amoxicillin or ampicillin is administered, a glowing red rash is almost always produced, which is characteristic of measles.
  • This rash begins 5-9 days after exposure to the drug, initially appears on the trunk and can generalize. It manifests itself in papules and spots (maculopapular exanthema).
  • The rash is probably caused by ampicillin immune complexes, resulting in polyclonal antibodies and B cell activation.

Vesicular rash and pustules

Chickenpox and herpes zoster Chickenpox and herpes zoster (shingles) are caused by varicella-zoster
virus (VZV or HHV-3).
The VZV is one of the eight known human pathogenic herpes viruses and causes:

  • in the prodromal phase (within the first 24-48 hours) of chickenpox: high fever, nausea, malaise;
  • in the exanthema phase (3 – 7 days later): vesicles that crust after 1-2 weeks;
  • Itch;
  • infections of nerve tissue;
  • latent infections in the ganglia of the dorsal nerve roots (nerve cell bodies near the spine or brain).

The initial infection causes chickenpox, after which the virus remains latent (not active) in the body.
In adults and the elderly, the virus becomes active again, causing the symptoms of herpes zoster.
Herpes zoster affects:

  • Joints
  • Trunk
  • Head area of the patient.

This disease can also cause:

  • pain and pinching,
  • Burn
  • Itch
  • mild fever (rare).

Usually, the localization along the course of nerve fibers (sciatica, intercostal nerves, etc.)

Eczema herpeticatum

  • Eczema herpeticatum (also known as eczema herpeticatum Kaposi) is a rare but severe diffuse skin infection caused by a herpes virus.
  • It is particularly evident in patients with:
  • Patients with atopic dermatitis seem to have a predisposition to the development of eczema herpeticatum.

Hand-foot-and-mouth disease

  • Hand-foot-and-mouth disease (HFMF) is an exanthema caused by a virus belonging to the group of picornaviruses of the genus Entero- and Coxsackie viruses.
  • Although enteroviruses can cause different types of rash, HFMD shows a common clinical manifestation and is easily recognizable.
  • The most common pathogen is the Coxsackie A 16 virus, but other Coxsackie viruses and enteroviruses may also be involved.
  • The infection has an incubation period of 3-7 days.
  • The main symptoms are:
    • Fever
    • lymph node swelling,
    • Appearance of oval, gray and painful vesicles of 2-8 mm in size. These arise after 1-2 days on:
      • Palm
      • Soles
      • Oral mucosa
      • Tongue.
  • Often the bubbles are surrounded by a halo.
  • The papular and vesicular lesions can also occur on other areas of the body, including the buttocks.
  • The rash in the mouth (also called enanthema) helps to distinguish HFDC from other causes of childhood exanthema, although cases without oral lesions have also been described.
  • The most commonly affected areas in the oral cavity are:
    • hard palate
    • Tongue
    • Oral mucosa.
  • Differential diagnosis must be excluded:

Papular exanthema

Infantile papular acrodermatitis Infantile papular acrodermatitis (also Gianotti-Crosti syndrome) is a disease of the skin, characterized by an exanthema with reddish papules.

The rash of Gianotti-Crosti syndrome is manifested:

  • on the limbs,
  • all of a sudden.

Molluscum contagiosum or molluscum molluscum Molluscum molluscum is a viral and highly contagious infection of the mucous membranes and skin that often occurs in children.

They are caused by a smallpox virus (molluscipoxvirus).

Usually they are skin-colored, shiny papules with a central dent in the form of a dome and with a size of 2 to 8 millimeters.
In about 30% of patients, a lesion may be surrounded by an eczematous reaction.

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