Intertrigo vs Heat Rash

Inflammation where opposing skin surfaces rub in a warm moist fold. Miliaria is an itchy or prickly eruption caused by blocked sweat ducts.

Research updated 2026-10-23

Key differences What is it?What it looks like Diagrams When it starts Triggers Treatment differences Outlook Complications When to get help Questions Daily Care

Key differences

The same eight facts on every condition comparison.

Usual age

Any age

Any age; babies most

Where

Armpits, groin, under breasts, belly folds

Trunk, folds, under clothing

Main sign

Raw, red, moist fold rash

Tiny prickly red bumps

Itch or pain

Sore, itchy

Prickly, itchy

Contagious

Long term

Returns if folds stay damp

Clears within days once cool

Scars

Who gets it

Heat, sweating, larger body size

Hot weather, overdressed babies

What is it?

Intertrigo

Heat Rash

What is it?

What it is
Inflammation where opposing skin surfaces rub in a warm moist fold.

What it is
Miliaria is an itchy or prickly eruption caused by blocked sweat ducts.

What it looks like

Intertrigo

A raised arm revealing a red patch within the underarm fold.

Intertrigo The irritated area follows the crease where skin surfaces meet.

Heat Rash

An upper back with numerous fine red bumps across the shoulders.

Heat Rash Many tiny bumps are scattered over a broad pink area.

Skin tones

In the skin

Trapped moisture and friction weaken the barrier where skin surfaces rub together. The damaged fold becomes inflamed, and infection may sometimes develop alongside it.

Blocked sweat ducts prevent sweat from reaching the surface normally. Trapped sweat irritates surrounding tissue at different levels of the skin.

When it usually starts

010203040506070+

Intertrigo. Can occur whenever skin remains damp and occluded.

Heat Rash. Any age; infants are particularly susceptible.

Causes and triggers

Causes

Moisture and friction damage the skin barrier in a warm enclosed area.

Blocked sweat ducts trap sweat at different levels of the skin.

Risk factors

Moisture, Friction, Occlusion

Hot humid weather, Occlusive clothing, Infancy

Trigger

● Intertrigo

● Heat Rash

Sweating

Can contribute

Friction

Can contribute

Not listed

Prolonged dampness

Can contribute

Not listed

Heat

Not listed

Can contribute

Occlusion

Not listed

Can contribute

Daily Care

Intertrigo

Heat Rash

Daily care

Habits that help

Clean skin folds gently and dry them completely
Pat dry; a cool hairdryer held safely away can help with difficult-to-reach folds.
Change damp clothing and underwear promptly
Choose loose, breathable fabrics to reduce heat and moisture.
Reduce rubbing between skin surfaces
A soft, clean absorbent layer may help; replace it when damp.
Keep the area cool during activity
Wash or rinse after heavy sweating and dry well afterwards.
Discuss cause-specific assessment
Persistent disease may need treatment for yeast, bacteria or another fold disorder.

Avoid

Avoid: Vigorous scrubbing and fragranced products
Irritation makes an already sore fold harder to heal.
Avoid: Treating every fold rash with a steroid alone
Yeast or bacterial infection may need specific treatment and persistent rash needs assessment.

Habits that help

Move to a cooler, less humid space
Cooling reduces sweating and helps the rash settle.
Wear loose, breathable clothing and lighter bedding
Change damp clothing promptly and avoid wrapping too warmly.
Use a cool bath or cool damp compress
Pat dry gently rather than rubbing the irritated skin.
Keep skin care light and simple
Wash gently and stop products that aggravate the rash.

Avoid

Avoid: Heavy ointments and tight occlusive clothing
These can trap heat and sweat against the skin.
Avoid: Continuing strenuous activity while overheated or unwell
Rest and cool down; dizziness, confusion or other heat-illness symptoms need urgent help.

Treatment differences

Treatment approach

Reduce moisture and friction while identifying any infection or other fold disorder. Antifungal, antibacterial or anti-inflammatory treatment should match the diagnosis; a steroid alone may be unsuitable.

Cooling the skin, reducing sweating and avoiding heavy occlusive products are the main measures. Persistent or severe symptoms need assessment rather than adding multiple creams.

Outlook

Long term

Fold irritation can improve when moisture and friction are reduced and any infection is treated. It often returns if the same conditions persist, so prevention remains part of care.

Heat rash usually settles after the skin cools and sweating is reduced. It may recur in hot or humid conditions; fever, marked pain or failure to improve needs review.