It is hard to say what caused the rash without seeing it. The number of papules, the presence of pus or water in any of them, whether there is reddish skin between them are all data that might be helpful. The rash might be an inflammation caused by infection, but an allergy might be a possible reason as well. The itching might be present in both cases.


You might want to visit a dermatologist to treat the rash. If infection (bacterial or fungal) is detected then adequate therapy would be given. Tell the doctor that your daughter is pregnant in order for him to reconsider whether the recommended therapy is safe to use in pregnancy. If an allergy is detected, it might be treated with antihistaminic medications.


You might want to visit a dermatologist as soon as possible if fever is present and the papules are full with water-like fluid. It might be a sign of varicella zoster, which is a reactivation of varicella infection. Since the virus might be transmitted to the baby via the placenta there is a possibility that it might hurt the baby. However, please do not panic because the varicella zoster infection is not very common and there is a big possibility that the rash is caused by something else. As mentioned before, visiting a dermatologist to check the rash is highly recommendable.