These red nodules require a doctor's examination first to be able to determine the cause. For that, you and your child can come to consult a dermatologist and genital specialist.
The nodule can be or be caused by:
contact dermatitis due to contact with certain objects atopic dermatitis due to allergic factors such as scabies or acne scabies The nodules should not be suppressed or solved. Also don't scratch it. Always keep the skin clean. And if a pimple appears after touching a certain object, then avoid that object until the doctor finds the exact cause.