Fifth's Disease is caused by a virus called Parvo Virus B19. It tends to affect school-aged children and toddlers usually around the Spring or the Fall. A child's first sign of infection with this rash will be bright cheeks, or sometimes people call it the 'slapped cheek rash;' the second sign could be fever, joint pain, another rash that is on the arms, the legs and the trunk. This rash can often look like a net or it can look lacy, so it is often called a lacy rash or a reticular rash. The rash of Fifth Disease tends to clear from the center outwards and can last anywhere from one to two weeks. The treatment for Fifth Disease is just supportive care, making your child comfortable with Tylenol or other pain relievers. An important thing to know about Fifth Disease is that it can be dangerous to pregnant women, so if you suspected your child had Fifth Disease you would want to keep them away from anyone you know is pregnant or have anyone who is pregnant and has been exposed to your child, talk to their doctor about it.