DermaTechRx Research Center

Infant Heat Rash

Heat rash is most common in babies and young infants when they become overheated, either because it is too warm outside or they are simply overdressed or have a fever. Although having an infant heat rash is common, it is likely not as common as many parents believe. It is typical to call any red rash kids may have when it is hot outside a heat rash.

Learning to distinguish heat rash from other common skin rashes, such as impetigo, eczema, folliculitis, and poison ivy, can be helpful so that you can properly treat and prevent this common rash. Though heat rash can affect anyone, newborns are most susceptible. As the name implies, infant heat rash is triggered in certain children when they become overheated, either because they are overdressed or because it is simply too hot outside. As they become hot and sweat, their sweat ducts become blocked and rupture.

Because a newborn’s sweat ducts aren’t fully developed, they rupture easily, trapping perspiration beneath the skin. This happens most often in hot weather, but it can occur anytime infants are dressed too warmly. Newborns who have high fevers or are in incubators can also develop blocked sweat ducts. The inflamed sweat ducts look like small bumps with a red halo around them and can usually be found grouped together under a child’s clothing and inside the folds of his skin, such as his neck, armpits, and groin. Infants who wear a hat may also get a heat rash on their forehead and scalp. Most often, heat rash goes away on its own. Severe forms of heat rash may need medical care, but the best way to relieve symptoms is to cool your skin and prevent sweating.

Mild heat rash doesn’t require any other treatment, but more severe forms may need topical therapies to relieve discomfort and prevent complications. Topical treatments may include things like calamine lotion to soothe itching or lanolin, which may help prevent duct blockage and stop new lesions from forming.  Topical steroids are often used in the most serious cases. Some anecdotal evidence supports the use of oral vitamin C supplements to help relieve heat rash also. However you should contact your health care provider if your child experiencing any of the following symptoms:

* A fever or other unexplained symptoms associated with the rash
* Any areas that look wet, oozing, or red, which are signs of infection
* A rash that extends beyond the diaper area
* A rash that is worse in the skin creases
* A rash, spots, blister, or discoloration and is younger than 3 months
* Blisters
* No improvement after 3 days of home treatment
* Significant scratching