Table: Some Viral Infections in Children That Cause a Rash-Merck Manual Consumer Version

Some Viral Infections in Children That Cause a Rash

Infection	Incubation Period*	Contagious Period†	Site of Rash	Nature of Rash in Children
Measles (rubeola)	7 to 14 days	From 2 to 4 days before until 4 days after the rash appears	Starts on the face around the ears and on the side of the neck Spreads to the trunk, arms, palms, soles, and legs	Begins a few days after fever and other symptoms and lasts 3 to 5 days Red and flat, then becomes raised and merges into larger red areas Mildly itchy
Rubella (German measles)	14 to 21 days	From 1 week before until 1 week after the rash appears (Except in newborns, who usually continue to be contagious for many months)	Starts on the face and neck Spreads to the trunk, arms, and legs	Begins a few days after fever and other symptoms and lasts 3 to 5 days Similar to measles rash but not as red and does not merge to form large red areas
Roseola infantum (exanthem subitum or pseudorubella)	About 5 to 15 days	Unknown	Starts on the trunk and usually spreads to the face, arms, and legs	Begins within a day after a high fever decreases and lasts for up to 3 days Red and flat, not itchy
Erythema infectiosum (fifth disease or parvovirus B19 infection)	4 to 14 days	From before the start of the rash until the rash appears	Starts on the cheeks ("slapped-cheek" appearance) Spreads to the arms, legs, and trunk	Begins a few days after fever and other symptoms and lasts 5 to 10 days Red, raised, blotchy areas with lacy patterns Can be itchy
Chickenpox (varicella)	7 to 21 days (most commonly 14 to 16 days)	2 days before the rash appears until all spots have crusted	Starts on the face and trunk Spreads to the arms and legs	Begins 1 to 2 days after the start of fever and other symptoms and lasts 4 to 7 days Small, red spots that become raised and form very itchy, round, blisters that then crust over
* The incubation period is the number of days between when a person becomes infected with a virus (or other infections organisms, such as bacteria) and when symptoms begin.
† The contagious period is the time period that an infected person can spread infection to others. Infections can spread during the contagious period even if people do not have symptoms.

Infection

Incubation Period*

Contagious Period†

Site of Rash

Nature of Rash in Children

Measles (rubeola)

7 to 14 days

From 2 to 4 days before until 4 days after the rash appears

Starts on the face around the ears and on the side of the neck

Spreads to the trunk, arms, palms, soles, and legs

Begins a few days after fever and other symptoms and lasts 3 to 5 days

Red and flat, then becomes raised and merges into larger red areas

Mildly itchy

Rubella (German measles)

14 to 21 days

From 1 week before until 1 week after the rash appears

(Except in newborns, who usually continue to be contagious for many months)

Starts on the face and neck

Spreads to the trunk, arms, and legs

Begins a few days after fever and other symptoms and lasts 3 to 5 days

Similar to measles rash but not as red and does not merge to form large red areas

Roseola infantum (exanthem subitum or pseudorubella)

About 5 to 15 days

Unknown

Starts on the trunk and usually spreads to the face, arms, and legs

Begins within a day after a high fever decreases and lasts for up to 3 days

Red and flat, not itchy

Erythema infectiosum (fifth disease or parvovirus B19 infection)

4 to 14 days

From before the start of the rash until the rash appears

Starts on the cheeks ("slapped-cheek" appearance)

Spreads to the arms, legs, and trunk

Begins a few days after fever and other symptoms and lasts 5 to 10 days

Red, raised, blotchy areas with lacy patterns

Can be itchy

Chickenpox (varicella)

7 to 21 days (most commonly 14 to 16 days)

2 days before the rash appears until all spots have crusted

Starts on the face and trunk

Spreads to the arms and legs

Begins 1 to 2 days after the start of fever and other symptoms and lasts 4 to 7 days

Small, red spots that become raised and form very itchy, round, blisters that then crust over

* The incubation period is the number of days between when a person becomes infected with a virus (or other infections organisms, such as bacteria) and when symptoms begin.

† The contagious period is the time period that an infected person can spread infection to others. Infections can spread during the contagious period even if people do not have symptoms.