Contagious / Infection Control

If you are a parent, it is probably safe to assume that you have received that dreaded call at one time or another.  You know the call.  You hear your phone ring/vibrate while in a meeting or getting coffee.  You look down at the caller ID: “Kid’s School.”  You let it go to voicemail, of course, so you have time to mentally prepare yourself for explaining why your child thought giving the class hamster a mohawk was a good idea.  Pressing play on the voicemail, you hear “Good afternoon, please come and pick up your child. They came to the nurse’s office and they have a fever.”  First, you let go a sigh of relief that Bobo has managed to keep his luscious locks.  But more importantly, you ask yourself When can my kiddo go back to school?

The truth of the matter is that it all depends on what is causing your child to not feel well.  Every cough, cold, rash, or upset stomach has unique characteristics for diagnosis and treatment.  And when you ask your provider when the little one can return to their friends’ playgroup or school, they are thinking of 2 specific characteristics of the pathogens that cause illnesses in children: the incubation period and the contagious period. 

The incubation period is the time between the exposure to an illness/infection and the start of symptoms.  Each cold or rash has different incubation periods.  The contagious period is the time during which a sick child’s disease can be spread to others.  Sometimes these 2 periods overlap, sometimes they don’t.  For instance, erythema infectiosum (slapped cheek rash or fifth disease) is contagious about halfway through its incubation period and stops being contagious when you see the characteristic cheek rash on your child.  In comparison, hand, foot, and mouth disease has an incubation period of up to 1 week but is not contagious until the symptoms are noticeable in your child, symptoms such as mouth sores and rash on the hands and feet.  By looking at the table below, we can see the incubation period and the contagious period of a lot of common childhood illnesses:

 DISEASE INCUBATION PERIOD (DAYS) CONTAGIOUS PERIOD (DAYS)

Skin Infections/Rashes:

Chickenpox 10-21 2 days before rash until all sores have crusts (6-7 days)

Fifth disease (erythema infectiosum) 4-14 7 days before rash until rash begins

Hand, foot, and mouth disease 3-6 Onset of mouth ulcers until fever gone

Impetigo (strep or staph) 2-5 Onset of sores until 24 hours on antibiotic

Lice 7 Onset of itch until 1 treatment

Measles 8-12 4 days before rash until 4 days after rash appears

Roseola 9-10 Onset of fever until rash gone (2 days)

Rubella (German measles) 14-21 7 days before rash until 5 days after rash appears

Scabies 30-45 Onset of rash until 1 treatment

Scarlet fever 3-6 Onset of fever or rash until 24 hours on antibiotic

Shingles (contagious for chicken pox) 14-16 Onset of rash until all sores have crusts (7 days)

(Note: No need to isolate if sores can be kept covered.)

Warts 30-180 Minimally contagious

Respiratory Infections:

Bronchiolitis 4-6 Onset of cough until 7 days

Colds 2-5 Onset of runny nose until fever gone

Cold sores (herpes) 2-12 Footnote 1

Coughs (viral) or croup (viral) 2-5 Onset of cough until fever gone

Diphtheria 2-5 Onset of sore throat until 4 days on antibiotic

Influenza 1-2 Onset of symptoms until fever gone

Sore throat, strep 2-5 Onset of sore throat until 24 hours on antibiotic

Sore throat, viral 2-5 Onset of sore throat until fever gone

Tuberculosis 6-24 months Until 2 weeks on drugs

(Note: Most childhood TB is not contagious.)

Whooping cough 7-10 Onset of runny nose until 5 days on antibiotic

Intestinal Infections:

Diarrhea, bacterial 1-5 Footnote 2

Diarrhea, giardia 7-28 Footnote 2

Notes

1.     Cold sores:  Less than 6 years old, contagious until cold sores are dry (4-5 days). No isolation if sores are on a part of the body that can be covered.  More than 6 years old, no isolation is necessary if beyond the touching, picking stage.

2.     Diarrhea precautions: Contagious until stools are formed.  Stay home until fever is gone, diarrhea is mild, blood and mucus are gone, and toilet-trained child has control over loose stools.  Shigella and E. coli 0157 require extra precautions.

There still are a lot of fevers in kids that aren’t easily categorized, or children that “just don’t feel good” with vague symptoms.  What we like to tell our patient’s parents is that, for the most part, if a child is fever-free for 24 hours and has enough energy and willingness to go to school, can stay well hydrated, and is able to let their teachers or school nurses know when they are not feeling well, they are most likely not contagious and safe to return to school…hamster haircuts and all.