Eczema and heat rash have clear differences, distinguished by their causes, affected areas, and symptoms.

The cause of heat rash is mainly due to blocked sweat pores, typically triggered by hot and humid environmental conditions; eczema, on the other hand, is usually caused by allergic factors such as food allergies, pollen, dust mites, animal fur, etc., and is also related to disorders of gastrointestinal function and indigestion.

The seasonal occurrence of the two conditions also differs. Heat rash usually occurs in the summer, while eczema can occur in any season and at any age.

The affected areas are also different. Heat rash typically appears on the chest, back, inside the elbows, neck, and forehead, whereas eczema can occur on any part of the body.

The clinical manifestations of the two are also different; heat rash involves inflammation of the sweat glands, with the skin turning red and a dense distribution of papules. Eczema, on the other hand, primarily features symmetrically distributed erythema and papules, and may also include exudation.