What Is Heat Rash?

June 13, 2018
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Heat rash is a skin condition that occurs when perspiration gets trapped beneath the surface of the skin as a result of clogged pores (sweat ducts). While it’s most common among infants with underdeveloped pores, heat rash can affect adults as well, especially in hot, humid weather. This annoying rash is also commonly referred to as prickly heat or miliaria.

What Are the Different Types of Heat Rash?

There are several forms of heat rash, and each differs depending on the depth of the affected sweat gland(s):

  • Miliaria crystallina – Superficial sweat ducts that become blocked typically result in the mildest form, called miliaria crystallina. This form may feature clear, fluid-filled blisters (papules).
  • Miliaria rubra – Another form that affects somewhat deeper sweat glands is often called prickly heat, or miliaria rubra. In this instance, red papules develop that are typically itchy or prickly feeling.
  • Miliaria pustulosa – Sometimes, the fluid-filled blisters become inflamed, resulting in a third form of heat rash known as miliaria pustulosa.
  • Miliaria profunda – A rare fourth form called miliaria profunda involves glands leaking into the lower layers of the skin (the dermis). Goose bump-like, flesh-colored lesions typically accompany this form of heat rash.

What Does Heat Rash Look Like?

Heat rash may appear as blisters on the surface of the skin. These blisters sometimes look like deep, red bumps that feel markedly itchy or prickly, and they may contain clear fluid. In people with darker skin tones, a heat rash may appear as a white globule surrounded by a darker circle of skin. Most rashes last about two or three days.

Among adults, heat rash tends to develop in the folds of the skin or where clothing rubs against the skin and causes friction. Heat rash in newborns is common on the neck, shoulders, and chest, but it can also occur in the creases of the elbows, armpits, and groin.

Is Heat Rash Painful?

Heat rash sometimes causes discomfort. Symptoms can involve a combination of mild itching that may worsen with sweating, moderate pain, a light burning sensation, and a prickly feeling. It’s not normal for a heat rash to cause intense pain, so reach out to a medical professional if this occurs.

Who Is at Risk for Heat Rash?

As previously mentioned, infants have the greatest chance of experiencing heat rash since their pores aren’t fully developed. Adults can also have a high risk—particularly adults who:

  • Are prone to excess sweating
  • Take certain drugs that can increase sweating, such as neostigmine and bethanechol
  • Routinely engage in high-impact exercise
  • Have certain conditions, including Morvan syndrome and type 1 pseudohypoaldosteronism

Can Heat Rash Be Prevented?

There are several steps you can take to lower your chances of getting a heat rash and help you stay cool no matter the weather. Keep these easy tips in mind to help prevent heat rash:

  • Avoid tight-fitting activewear
  • Opt for breathable cotton over synthetic fabrics
  • Stay away from heavy creams and lotions that can clog your pores
  • If possible, work out indoors during the hot summer months
  • Stay hydrated by drinking plenty of water and avoiding unnecessary time in the sun
  • Choose soaps that don’t contain dyes or fragrances

How Do You Treat Heat Rash?

Heat rash generally clears up on its own, especially if you can cool the skin and avoid the need to sweat. The best way to cool down and stop sweating, of course, is to spend time in a cool, air-conditioned indoor environment. Try switching to light, loose-fitting clothing and stay in the shade if you can’t readily retreat indoors.

A heat rash that persists despite your best efforts to cool down can usually be treated by applying an over-the-counter (OTC) hydrocortisone cream once or twice a day. Taking an OTC antihistamine as directed can also help ease itching.

When to Visit PhysicianOne Urgent Care for Heat Rash

Cooling off and eliminating the need to sweat are often sufficient to resolve heat rash. If symptoms persist for more than a few days, though, it’s a good idea to visit PhysicianOne Urgent Care. You should also come see us if your discomfort worsens or if symptoms of an infection emerge. Possible signs of a severe or infected heat rash include:

  • Warmth
  • Swelling
  • Redness
  • Tenderness
  • Fluid or pus drainage
  • Fever and/or chills
  • Swollen lymph nodes near the rash
  • Nausea
  • Intense pain

The clinicians at PhysicianOne Urgent Care have ample experience caring for adult and pediatric patients with heat rash and other heat-related conditions, such as dehydration and sunburns. We can provide topical treatments to soothe a painful rash, prescribe medications to clear infections, and administer IV fluids to resolve dehydration, if appropriate.

We’ve Got You

If you or a loved one is experiencing signs of heat rash or a possible infection, PhysicianOne Urgent Care’s experienced clinicians are here to help. Our fully equipped and physician-led locations throughout Connecticut, Massachusetts, and New York are open 365 days per year during extended hours and never require appointments, although we offer convenient online appointment scheduling for patients who’d prefer to plan ahead. What’s more, we’re proud to be among a select few urgent care providers to offer 24/7 telemedicine services that allow patients to consult with our clinicians from anywhere at any time.

Have questions? Contact PhysicianOne Urgent Care at 1-860-650-3848 to speak with one of our friendly professionals today. We provide heat rash treatment to patients of all ages and accept most health insurance plans.

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I had to take my son in for an ear infection following a sudden change in temperament at daycare. He was inconsolable the entire car ride but when we got there and by the time we left this care facility he was back to his normal happy go lucky little two year old boy. I highly recommend PhysicianOne Urgent Care.
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