Miliaria: Understanding Sweat Rash


Today’s topic is Miliaria, commonly known as sweat rash.

Sweat rash is caused by the accumulation of sweat when a part of the sweat duct or sweat pore is blocked, preventing sweat from being excreted to the epidermis.

Depending on where the sweat duct is blocked, sweat rash can be classified into three types as shown in the picture above:

1) Miliaria Crystallina
2) Miliaria Rubra
3) Miliaria Profunda

Sweat rash usually affects newborns or people who sweat a lot in hot, humid areas, and occurs equally regardless of race or gender.

1) Miliaria Crystallina

This presents as transparent, shallow blisters about 1mm in size scattered across the skin, usually without inflammation or symptoms. It commonly occurs in the armpits, head, neck, and upper body, and generally heals naturally without treatment.

2) Miliaria Rubra

This type is usually accompanied by severe itching and appears as red nodules or blisters, mainly on the torso, arms, legs, and neck, but not on the face.


3) Miliaria Profunda

This type usually occurs in tropical climates after a long period of suffering from Miliaria Rubra. There is no inflammation or itching, but sweat gland function is decreased or lost.

The fundamental treatment for sweat rash is to stay in a cool environment, enabling sweat to evaporate well with the help of air conditioning or fans. Taking a large amount of Vitamin C can also be beneficial.

Miliaria Crystallina usually improves on its own, while Miliaria Rubra can be helped by using mild to moderate topical steroids if there is inflammation or itching.

Commonly seen Miliaria Crystallina usually has no symptoms and improves on its own, while Miliaria Rubra can be quite itchy, and topical steroids or antihistamines can aid in treatment. Above all, it’s important to stay cool.

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