Infants with something like prickly heat on their foreheads may have a corn rash, acute eczema, hand-foot-mouth disease, rubella, and toddler’s emergency rash. 1. Corn Rash: The hot and humid environment leads to the blockage of sweat pores, at this time, small pimples or blisters can occur rapidly. 2. Acute eczema: because of the stimulation of a variety of factors, triggered by the inflammation of the skin, so that the skin appears polymorphic herpes. 3. Hand, foot and mouth disease, rubella, toddler’s emergency rash: when infants are infected by viruses, the viral attack will appear like prickly heat rash. Finally, the appearance of infant forehead growth like prickly heat please go to the hospital in time to check, follow the doctor’s instructions for treatment.