A syndrome of cutaneous changes associated with sweat retention and extravasation of sweat at different levels in the skin. miliaria rubra, or prickly heat, results from apocrine duct obstruction. the sweat then seeps into the epidermis, producing pruritic erythematous papulovesicles. (from dorland, 27th ed)

Miliaria, commonly known as heat rash, sweat rash, or prickly heat, is a skin disease marked by small, itchy rashes due to sweat trapped under the skin by clogged sweat-gland ducts. Miliaria is a common ailment in hot and humid conditions, such as in the tropics and during the summer...