Children in large groups are breeding grounds for the organisms that cause illness. Here is a look at the top five infectious illnesses that keep kids home from school and child care.

COLDS

Children typically have six to 10 colds a year and also tend to have more severe and longer lasting symptoms than do adults. The good news is that you or your child should be feeling better in about a week. If symptoms aren't improving in that time, see your doctor to make sure your child doesn't have a bacterial infection in the lungs, sinuses or ears.

STOMACH FLU

The second most common childhood illness is gastroenteritis, more commonly known as the stomach flu. This illness can lead to dehydration. Signs and symptoms of dehydration include: excessive thirst, dry mouth, severe weakness or lethargy, nausea or vomiting.

EAR INFECTION

Middle ear infections occur most often in babies and children between the ages of 4 months and 5 years. Most children have had at least one ear infection by the time they're 3 years old. It can be difficult to distinguish between ear infections caused by bacteria and those caused by viruses. For most otherwise healthy kids over 6 months of age, watchful waiting is a reasonable choice for suspected ear infections. They often clear up without antibiotics. But this may not be the best option for every child. If your child has recurrent ear infections, hearing loss or other health conditions, your doctor may suggest antibiotics or ear tubes.

PINK EYE

Also know as conjunctivitis, it is an inflammation of the clear membrane that covers the white part of the eye and lines the inner surface of the eyelids. When caused by viruses or bacteria, it is highly contagious. Warm or cool compresses may ease your child's discomfort. Signs and symptoms of pink eye include: redness and or itchiness in one or both eyes, blurred vision and sensitivity to light, and tearing.

SORE THROAT

Dry scratchiness and painful swallowing are the hallmarks of a sore throat but it is most often a symptom of another illness — usually a viral infection such as a cold or the flu. Most sore throats usually go away on their own in a few days. Only a small portion of sore throats are the result of strep throat. Strep throat is most common in children between the ages of 5 and 15, but can affect people of all ages. Fevers above 101°F are common in strep throat, and swallowing can be so painful that your child may have difficulty eating. Antibiotics are required to combat strep throat.

The single most important thing your child can do to prevent illness is to wash his or her hands thoroughly and frequently. Despite your best efforts, your child is going to get sick — especially during his or her first few years of contact with larger groups of children. But a child's immunity improves with time. School-age children gradually become less prone to common illnesses and recover more quickly from the diseases they do catch.

Source: CDC