Picture of Miliaria Crystallina
Miliaria crystallina is a skin condition that develops after sweat glands in the stratum corneum become obstructed. Clear, thin vesicles form on the skin. Different factors may trigger the rash including sunburn, fever, or profuse sweating in an excessively hot and humid environment. Miliaria crystallina most commonly forms on the face, scalp, trunk, armpit, groin, and between the fingers. The vesicles resolve after the underlying cause of the condition goes away.
Text Reference: Dermatology, 1st edition: "Miliaria"