I wouldn't worry about fifths disease unless he is running a low grade fever and showing cold like symptoms. Fifths disease is a viral infection that no one has any medication for. They merely treat the symptoms and not the virus. My son was diagnosed with fifths disease 6 weeks ago, although he has made a full recovery. If you are concearned it may be fifths disease your doctor can run a blood test to see if it has passed to you or not. Fifths disease is most contagious a week before the rash breaks out, so that would mean if it is fifths then you have already possibly caught it. The symptoms of fifths disease in adults are only mentioned as swelling and pain in your joints, particularly your hands and knees.
If you are out of your first trimester then your doctor normally wouldnt be very concearned. It is your first trimester that they worry about you catching and passing the virus through your placenta.
I don't know about chicken pox, I have never had it, and neither have my boys. I know with being pregnant that chicken pox can be extremely worrisome to pregnant women and adults who have not been in contact or have had chicken pox.
I agree with Joy, I would take him to see his pediatrician. The ER will probably give him a cream, call it dermitis and send you home. Also make sure you let your OB know if it is either chicken pox or fifths disease.
It also could be a rash from the heat, or from laundry detergant, some washers do not rinse properly on occassion and can cause the detergent to come out of the fabric when a child sweats or gets wet, causing an irritation.
You can always try Aveno Colloidal oatmeal bath, and my OB told me to use Diaper rash cream on my son as it relieves itching and burning of most all rashes.
Good luck and I hope he is okay.
It looks like chicken pox to me. You should call his pediatrician in the AM and get him in (don't go to the ER because it'll be a waste of time and money!). Let them know you're pregnant and are worried it could be Fifths Disease or chicken pox (especially if you've never had chicken pox).
Kids also get heat rashes during the summer. But those dots are tiny and usually pink to red. These look more like chicken pox bumps to me!
*BUMP*
Sorry girls, but this really has me worried b/c someone mentioned Fifths Disease and it can cause serious complications for a pregnant woman and may actually cause her to miscarry.
Any info?!?