Miliaria occurs when the sweat gland ducts get plugged due to dead skin cells or bacteria such as Staphylococcus Epidermidis, a common bacterium that occurs on the skin which is also associated with acne.
The trapped sweat leads to irritation (prickling), itching and to a rash of very small blisters, usually in a localized area of the skin.
You should see a Skin Doctor to see if that is what it really is and avoid hot and humid conditions, avoid wearing occlusive clothing and avoid activities which cause sweating.
For the itch you can use a prickly heat powder, hydrocortisone 1 percent preparation (OTC) twice a day or other anti itch preparations like calamine lotion.
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