Houston Hives: Humidity Breeding Sunscreen Yeast?

By Franklin Everett Shaw

January 1, 2026

Is that persistent rash on your back really acne? In Houston’s sweltering humidity, it might be something else entirely: pityrosporum folliculitis. This yeast-based skin condition thrives in our warm, moist climate, often mimicking acne or heat rash, leading to misdiagnosis and ineffective treatments. Let’s dive into how Houstonians can identify, treat, and prevent this frustrating skin issue.

Pityrosporum folliculitis, also known as Malassezia folliculitis, is an infection of the hair follicles caused by a type of yeast called Malassezia. This yeast is a normal resident of the skin, but in certain conditions, like high humidity and occlusion (think sunscreen and sweaty workout clothes), it can overgrow and cause inflammation.

So, how do you tell the difference between pityrosporum folliculitis and regular acne, especially in Houston? Acne typically presents with blackheads, whiteheads, and larger, inflamed pimples. Pityrosporum folliculitis, on the other hand, usually appears as small, uniform, itchy bumps, often on the back, chest, and upper arms. The itchiness is a key differentiator.

Houston’s climate is a perfect breeding ground for this yeast. The high humidity creates a moist environment on the skin, and the heavy sun encourages the use of occlusive sunscreens, trapping moisture and creating a feast for the Malassezia yeast.

Here’s a step-by-step guide to identifying pityrosporum folliculitis:

1. Location: Is the rash primarily on your back, chest, or upper arms? These are common areas.
2. Appearance: Are the bumps small, uniform in size, and itchy? Acne tends to be more varied.
3. Itchiness: Is the rash intensely itchy, especially after sweating? This is a major clue.
4. Lack of Response to Acne Treatments: Have you been using benzoyl peroxide or salicylic acid without improvement? This suggests it’s not acne.

Now, let’s talk treatment. The good news is that pityrosporum folliculitis is treatable with over-the-counter antifungal medications.

Here’s a Houston-specific treatment plan, readily available at pharmacies like CVS on Westheimer or Walgreens on Holcombe:

1. Antifungal Body Wash: Purchase a body wash containing ketoconazole or selenium sulfide. Nizoral (ketoconazole) and Selsun Blue (selenium sulfide) are readily available. Use this body wash daily, leaving it on the affected areas for 5-10 minutes before rinsing. This allows the medication to penetrate the hair follicles.
2. Antifungal Cream: Apply an over-the-counter antifungal cream containing clotrimazole or miconazole to the affected areas twice daily. These creams are available under various brand names at most drugstores.
3. Consider Head & Shoulders: Head & Shoulders shampoo contains zinc pyrithione, another antifungal agent. It can be used as a body wash in a pinch, though ketoconazole or selenium sulfide are generally more effective.

Important Note: Consistency is key. You need to use these treatments regularly for several weeks to see results. Don’t expect overnight miracles.

But treatment is only half the battle. Prevention is crucial, especially in Houston’s challenging climate.

Here’s a preventative skincare routine tailored for Houston’s humidity:

1. Shower Immediately After Sweating: Don’t let sweat sit on your skin. Shower as soon as possible after exercising or being outdoors in the heat.
2. Use a Gentle, Non-Comedogenic Cleanser: Avoid harsh soaps that can strip your skin of its natural oils. Look for cleansers labeled “non-comedogenic,” meaning they won’t clog pores. Cetaphil and CeraVe are good options.
3. Choose a Lightweight, Oil-Free Sunscreen: Sunscreen is essential in Houston, but heavy, occlusive sunscreens can trap moisture. Opt for a lightweight, oil-free formula. EltaMD UV Clear Broad-Spectrum SPF 46 is a popular choice.
4. Wear Loose-Fitting, Breathable Clothing: Avoid tight-fitting clothes that can trap sweat against your skin. Choose loose-fitting, breathable fabrics like cotton or linen.
5. Consider a Weekly Antifungal Body Wash: Even after the rash clears, consider using an antifungal body wash once a week to prevent recurrence.

One common mistake developers make when dealing with skin conditions is assuming that all rashes are the same. They might try treating pityrosporum folliculitis with acne medications, which can actually worsen the condition. Another pitfall is not being consistent with treatment. Antifungal medications need to be used regularly for several weeks to be effective.

Here’s a real-world scenario: Imagine a Houston resident, Sarah, who works outdoors. She develops a persistent, itchy rash on her back that she initially dismisses as heat rash. She tries using over-the-counter acne washes, but the rash doesn’t improve. Frustrated, she finally sees a dermatologist who diagnoses her with pityrosporum folliculitis. The dermatologist prescribes a ketoconazole body wash and advises her to shower immediately after work and wear breathable clothing. Within a few weeks, Sarah’s rash clears up, and she’s finally comfortable in her own skin again.

When should you seek a dermatologist in the Houston area? If your rash doesn’t improve after several weeks of over-the-counter treatment, or if it’s severe or widespread, it’s time to see a dermatologist.

Here are a few dermatologists in Houston specializing in fungal skin conditions:

• Dr. Maryam M. Asgari, MD: Located in the Texas Medical Center, Dr. Asgari specializes in medical dermatology, including fungal infections.
• Houston Dermatology Associates: This practice has multiple locations throughout Houston and offers a wide range of dermatological services.
• U.S. Dermatology Partners Houston Clear Lake: This clinic focuses on general dermatology, surgical dermatology, and cosmetic dermatology.

These dermatologists can provide a definitive diagnosis and prescribe stronger antifungal medications if needed. They can also rule out other skin conditions that may be causing your symptoms.

Don’t let pityrosporum folliculitis ruin your Houston summer. By understanding the condition, identifying it correctly, and following a consistent treatment and prevention plan, you can keep your skin clear and comfortable, even in the face of Houston’s humidity. Remember, if in doubt, consult a dermatologist. Your skin will thank you.