The photos show many similar-looking inflamed follicle-centered bumps and small pustules across the upper chest, shoulders, and back, with dark marks from older spots. This can be truncal acne, but the very uniform pattern also raises a strong possibility of Malassezia (yeast) folliculitis. These can coexist. Malassezia folliculitis commonly affects the upper trunk and arms with monomorphic red papules/pustules and may be mistaken for acne. - Fitzpatrick's Dermatology, p. 2989
Important: stop using steroid combination creams
Do not restart:
- Diprobate (a potent topical steroid)
- Terbinafine + mometasone lotion, unless a dermatologist specifically tells you to use it for a confirmed diagnosis
Mometasone and other steroids can temporarily reduce redness, making it look better, but they do not treat acne and can trigger or worsen acne-like folliculitis. Steroids may also promote Malassezia folliculitis. - Harrison’s Principles of Internal Medicine, p. 434
What to do next
Book a follow-up with a dermatologist, ideally soon, and ask specifically:
- “Could this be Malassezia folliculitis rather than, or together with, acne?”
- Request a KOH examination from a pustule/skin scraping for yeast. This is a useful clinic test for Malassezia.
- If active pustules persist, ask whether a bacterial culture is needed before taking another antibiotic.
Since minocycline did not help and the eruption recurred after steroid-containing treatment, it is better to confirm the cause rather than repeating the same medicines.
A reasonable treatment discussion to have with your dermatologist
If it is mainly acne
- A benzoyl peroxide 4% to 5% body wash once daily in the shower, left on 2 to 3 minutes then rinsed. It can bleach towels/clothes.
- A topical retinoid such as adapalene or prescription tretinoin/trifarotene for the whole affected area, not only individual spots.
- If an oral antibiotic is needed, it should be time-limited and used with benzoyl peroxide/topical therapy, not alone.
- Severe, scarring, or treatment-resistant truncal acne may need dermatologist-supervised isotretinoin.
The 2024 acne guideline supports benzoyl peroxide and topical retinoids, with oral antibiotics only as part of combination treatment; isotretinoin is considered for severe or treatment-resistant acne. See the
AAD acne guideline (PMID 38300170).
If it is Malassezia folliculitis
- Doctors often prescribe an antifungal regimen, commonly ketoconazole or another azole wash/shampoo applied to the chest, shoulders, and back, sometimes with a short course of an oral antifungal if extensive.
- It often recurs, so a maintenance antifungal wash may be advised.
- Antibiotics and steroid creams can make it persist or return in some people.
Do not self-start oral antifungal tablets. They can interact with other medicines and may require liver-related safety considerations.
Safe habits now
- Shower soon after sweating/exercise.
- Wear loose, breathable clothes and change sweaty shirts promptly.
- Avoid oily body lotions, hair oils running onto the shoulders, and heavy occlusive products.
- Do not scrub, squeeze, or pick. This increases the dark marks and scarring.
- Wash gym clothing, bedsheets, and towels regularly.
- The black/brown marks are likely post-inflammatory hyperpigmentation. They fade slowly after new inflammation is controlled, often over months.
Get urgent care if
You develop fever, rapidly spreading redness, severe pain, large boils, drainage, or you are immunocompromised.
The key point is: this needs a reassessment for yeast folliculitis versus acne, and steroid-containing creams should not be your ongoing treatment.