What is the difference between heat rash and eczema?

Miliaria and eczema have significant differences in several aspects: 1. Etiology: Miliaria is primarily caused by a hot and humid environment, where sweat does not evaporate easily, leading to blocked sweat glands and subsequent inflammatory reaction. Eczema, on the other hand, may be triggered by various factors, including heredity, abnormal immune function, environmental temperature changes, allergies, and others. 2. Affected Areas: Miliaria commonly occurs in areas prone to sweating and friction, such as the neck, armpits, trunk, and forehead. Eczema can appear on any part of the body but is more commonly found on areas such as the lower legs, forearms, ears, hands, and feet. 3. Seasonal Incidence: Miliaria is closely related to high temperature and humidity in summer, while eczema can occur throughout the year, being more common during winter and spring seasons. 4. Clinical Manifestations: Miliaria presents as small papules, papulovesicles, or vesicles the size of a pinhead to a needle tip on the skin, possibly accompanied by itching and a prickling sensation. Eczema presents with symptoms such as erythema, papules, vesicles, exudate, and thickened skin, with significant itching.