What is another name for heat rash?

Alternative Names for Heat Rash

The medical term for heat rash is "miliaria," which is the most commonly used clinical name for this condition. 1

Types of Miliaria and Clinical Presentation

Heat rash (miliaria) is a self-limiting cutaneous condition that develops from skin exposure to:

• Humid climates
• Occlusion
• Raised temperatures

The condition forms when there is obstruction of the eccrine sweat ducts, leading to characteristic skin manifestations. Based on the depth of sweat duct obstruction, miliaria can be classified into different types:

1. Miliaria crystallina - Most superficial form
2. Miliaria rubra - Deeper obstruction, more common form
3. Miliaria profunda - Deepest form of obstruction

Clinical Features

Miliaria typically presents as:

• Groups of 1-3 mm sweat-filled vesicles in the epidermis 1
• In miliaria rubra, there are erythematous papules and vesicles
• In severe cases, bullous presentations can occur 1

Pathophysiology

The condition develops due to:

• Obstruction of eccrine sweat ducts
• Retention of sweat in the skin
• Inflammatory response to the retained sweat

Heat and humidity are primary triggers, causing excessive sweating that leads to occlusion of sweat ducts. This results in the characteristic rash and associated symptoms like itching and discomfort 2.

Associated Conditions and Complications

If extensive or severe, heat rash can lead to:

• Heat intolerance
• Reduced sweating ability
• Impaired thermoregulation 3

Research has shown that the critical amount of surface area affected by heat rash that leads to heat intolerance appears related to the specific region of the body and associated sweating responses 3.

Differential Diagnosis

Heat rash should be distinguished from other heat-related skin conditions such as:

• Heat urticaria - characterized by itchy erythema and well-demarcated weals appearing soon after heat exposure 4
• Sweat dermatitis - an irritant inflammatory dermatosis occurring due to prolonged exposure of retained sweat over the skin 5

Management

Management of heat rash primarily involves:

1. Cooling the affected area
2. Reducing sweating
3. Preventing secondary infection
4. Relieving symptoms

Prevention

To prevent heat rash:

• Avoid excessive heat and humidity when possible
• Wear loose, lightweight clothing
• Use air conditioning or fans to stay cool
• Take cool showers after sweating
• Keep skin dry and clean

Understanding the proper terminology for heat rash helps healthcare providers accurately diagnose and communicate about this common condition, especially in hot and humid environments.