Itchy Rash in Underarms: Causes & Remedies

Key takeaways:

• Rashes in the underarms are often caused by irritation, allergies, fungal infections, or skin conditions.
• Most cases can be treated with home remedies, but persistent or severe rashes may need medical attention.
• Keeping the area clean and dry is essential for both prevention and recovery.

Experiencing an itchy rash in your underarms can be uncomfortable and frustrating. This sensitive area is prone to irritation from sweat, clothing, and personal care products. In some cases, the rash may be a sign of an allergic reaction or a fungal infection, while other times, it may be due to skin conditions like eczema.

Understanding the common causes of an itchy underarm rash and knowing how to treat it can help you manage your symptoms and find relief. This article covers the possible causes, remedies, and when to seek medical attention for an underarm rash.

Common causes of an itchy armpit rash

An itchy rash in the underarms can develop for many reasons. Here are some of the most common causes:

Irritation from deodorants or antiperspirants

Many deodorants or antiperspirants contain chemicals and fragrances that can irritate sensitive skin. This irritation can lead to redness, itching, and a rash in the underarm area, especially if you shave there regularly.

The combination of shaving and applying harsh products can cause small cuts in the skin, increasing sensitivity to these chemicals. Switching to fragrance-free or hypoallergenic products can help reduce this irritation.

Contact dermatitis

Contact dermatitis occurs when the skin reacts to an irritant or allergen, leading to a red, itchy rash. This can be caused by fabrics in clothing, soaps, or laundry detergents.

Metals, like nickel found in razors or jewelry, can also trigger contact dermatitis in the underarm area. If untreated, contact dermatitis can worsen, leading to blisters or skin peeling, making it crucial to identify and remove the irritant early on.

Fungal infections

Underarms are warm, moist areas, making them prone to fungal infections, especially Candida (yeast). Symptoms of a fungal infection include redness, itching, and a white, scaly rash.

The infection thrives in areas that remain damp, so keeping the underarm area dry is crucial to preventing and treating these rashes. Recurring infections may require prescription antifungal medications for more effective treatment.

Eczema

Eczema is a chronic skin condition that causes inflamed, itchy patches of skin. Underarm eczema can flare up due to sweat, heat, or irritation from products.

Managing eczema involves moisturizing the skin and avoiding known triggers, such as allergens or irritants. Flare-ups can be particularly bothersome in warm weather or after exercise, so maintaining a proper skincare routine is essential.

Heat rash

Heat rash develops when sweat becomes trapped in the sweat ducts. This can cause red bumps, itching, and a stinging sensation.

Heat rash is common in hot, humid environments or after intense physical activity. Preventing heat rash involves staying cool, wearing breathable fabrics, and avoiding excessive sweating in warm conditions.

Read our full guide on different types of rashes for more.

Other symptoms of an itchy armpit rash

In addition to itching, an underarm rash may come with other symptoms that can help you determine the cause.

Redness and swelling

Red, swollen skin may suggest an allergic reaction, infection, or irritation from a product or fabric. In more severe cases, the skin can become tender and painful, indicating the need for medical attention.

Blisters

Blisters can form in response to friction or an allergic reaction. If you notice blisters, it’s essential to avoid further irritation to prevent infection. Applying a protective dressing over the affected area may help in preventing the rash from worsening.

Scaling or peeling skin

Dry, flaky skin is often a symptom of eczema or fungal infections. Keeping the skin moisturized or using antifungal treatments can help reduce scaling. Peeling skin may also indicate that the rash is healing, but it is essential to monitor for signs of infection during this process.

Read our full guide on rash symptoms for more.

Getting short-term relief from an itchy armpit rash

When dealing with an itchy underarm rash, you’ll want immediate relief from the discomfort. Here are some treatments that can help soothe the skin:

Cold compress

Applying a cold compress can reduce itching and inflammation. It helps to cool the area and soothe irritation caused by rashes, particularly from allergic reactions or heat. Reapplying cold compresses throughout the day can offer continuous relief.

Fragrance-free moisturizers

Using a gentle, fragrance-free moisturizer can help soothe dry, irritated skin, particularly in cases of eczema.

Look for products containing calming ingredients like colloidal oatmeal or aloe vera. Applying moisturizer immediately after a shower can help lock in moisture and prevent dryness.

Over-the-counter hydrocortisone cream

Hydrocortisone cream can reduce itching and inflammation associated with contact dermatitis or eczema.

Applying this cream directly to the rash can help provide temporary relief. It’s important to use it as directed to avoid thinning of the skin with prolonged use.

Getting long-term relief or a cure for an itchy armpit rash

While short-term remedies can help alleviate symptoms, long-term relief may require more specific treatments, especially for chronic conditions like eczema or fungal infections.

Antifungal creams

For fungal infections like Candida, an antifungal cream or powder can help clear the infection. Be sure to keep the area clean and dry to prevent the infection from returning. In more persistent cases, prescription-strength antifungal medications may be necessary.

Prescription steroids

If over-the-counter treatments aren’t effective, a healthcare provider may prescribe stronger corticosteroids to help manage more severe cases of eczema or contact dermatitis. These medications are typically used for short periods to reduce inflammation and prevent flare-ups.

Avoiding triggers

For individuals prone to allergic reactions or contact dermatitis, identifying and avoiding the trigger (such as specific deodorants or fabrics) is key to preventing future rashes. Keeping a journal of new products and any reactions can help identify problem substances quickly.

Read our guide on how to get rid of a rash quickly for more.

Preventing itchy armpit rashes

Prevention is crucial in managing underarm rashes. Here are some effective strategies to reduce the risk of developing a rash:

Use hypoallergenic products

Switching to fragrance-free or hypoallergenic deodorants, soaps, and laundry detergents can minimize the risk of irritation.

Look for products specifically designed for sensitive skin to avoid common allergens like fragrances and dyes.

Keep the area dry

Since moisture can contribute to fungal infections and heat rash, keeping the underarm area dry is essential. Use talcum powder or wear breathable fabrics to reduce sweating.

If you’re prone to excessive sweating, using an antiperspirant designed for sensitive skin can also help manage moisture levels.

Avoid tight clothing

Tight clothing can cause friction, leading to irritation or rashes. Opt for loose-fitting, breathable fabrics like cotton to allow airflow and prevent moisture buildup. Avoid synthetic fabrics, which can trap heat and irritate the skin further.

When to see a doctor for an itchy armpit rash

In most cases, an itchy armpit rash will resolve with at-home treatments. However, if symptoms persist or worsen, it's important to consult a healthcare provider for a proper diagnosis and treatment plan.

You should see a doctor if:

• The rash lasts longer than a week without improvement.
• You experience severe itching or pain that affects your daily activities.
• The rash is accompanied by a thick discharge or foul odor, which may indicate an infection.

You should go to the emergency room if:

• You have trouble breathing or swallowing.
• The rash spreads rapidly or is accompanied by a high fever.

Read our full guide on when to worry about a rash for more.

Questions to ask your doctor about an armpit rash

If you're visiting a healthcare provider for your rash, here are a few important questions to ask:

• What could be causing my rash?
• Do I need medication to treat it?
• How can I prevent this from happening again?
• What should I look out for to know if the rash is getting worse?

Frequently asked questions: armpit rashes

Armpit rashes are common, but many people have specific concerns depending on the severity or location of their symptoms. Below are answers to some frequently asked questions about armpit rashes.

What if your armpit rash is only in one armpit?

A rash limited to one armpit may be caused by localized irritation, such as from shaving, a specific deodorant, or an allergic reaction.

It’s essential to monitor the rash for changes and avoid further irritation. Switching to a hypoallergenic deodorant or avoiding products with harsh chemicals may reduce symptoms.

Is an armpit rash a sign of a sexually transmitted infection (STI)?

In most cases, an armpit rash is not a sign of an STI. However, some infections, like syphilis, can cause rashes that may affect different areas of the body, including the underarms.

If you’re concerned, it’s best to consult with a healthcare provider for proper diagnosis and treatment. Regular testing for STIs can also help rule out any concerns.

Is an armpit rash a sign of cancer?

Armpit rashes are generally not a sign of cancer. However, some types of cancer, like lymphoma, can cause rashes or lumps in the underarm area.

If you notice unusual symptoms, such as swelling or lumps, it’s important to seek medical evaluation. Early detection is crucial for more serious conditions.

Managing an itchy underarm rash

Itchy underarm rashes are a common problem that can result from a variety of causes, including allergies, infections, and skin conditions. While most rashes can be treated with simple remedies, it’s important to know when to seek medical attention, especially if the rash persists or worsens.

By understanding the causes and symptoms of an underarm rash and applying the appropriate treatments, you can effectively manage the condition and reduce discomfort. Long-term relief often requires preventive measures such as using hypoallergenic products, keeping the area dry, and wearing breathable fabrics.

If your symptoms persist despite treatment, consulting with a healthcare provider is essential to ensure there’s no underlying condition that requires attention. Identifying the cause and following through with appropriate care can help you achieve healthier skin and prevent future occurrences.

General Medicine follows a strict editorial process, including using real experts to write our articles, vetted primary sources, fact-checking, a secondary medical review, and updates as necessary. This article was medically reviewed and fact checked by Dr. Pallabi Sanyal-Dey, MD.

Sources

Centers for Disease Control and Prevention. "Fungal Diseases: Types of Fungal Diseases." CDC, 2023, https://www.cdc.gov/fungal/diseases/index.html.

MedlinePlus. "Rash Evaluation." MedlinePlus, 2023, https://medlineplus.gov/ency/article/000880.htm.