Ollowen Guides · When It Flares

When it’s fungal — and why steroid makes it worse

Two different fungal problems sit next to eczema, and both are worth knowing about. One is a rash that was never eczema and gets steadily worse under the cream treating it. The other is a yeast that may be driving eczema that won't settle on an adult's face and neck.

A plain-language explainer · Not medical advice — only a doctor can tell these apart, and it often needs a test

The trap: tinea incognito

Tinea incognito is the name for a fungal infection that was mistaken for dermatitis and treated with topical steroids. The steroid calms the inflammation, so the rash looks less angry and feels less itchy — and the fungus, freed from the immune response holding it back, spreads. The more steroid goes on, the more extensive and the less recognisable the infection becomes. It's a genuine trap, and the treatment feels like it's helping right up until it obviously isn't.

Tinea corporis (ringworm on the body) is specifically listed among the things confused with eczema, and clinical appearance alone is described as unreliable — testing is what settles it. Even on the eyelids there is a version, tinea blepharociliaris, routinely misdiagnosed as blepharitis or eczema, leading to treatment that doesn't work and symptoms that keep coming back.

What should make you ask

The question to ask is simple: "could this be fungal, and is it worth testing?" A scraping is a small thing to do and it ends the argument.

The other one: Malassezia and head-and-neck eczema

Malassezia yeasts live on everyone's skin and need lipids to grow, which is why they colonise the sebum-rich head, face and neck rather than the limbs or trunk. In adults whose atopic dermatitis is concentrated there, that turns out to matter. In one series, 79% of adult patients with head-and-neck AD had positive skin prick tests to Malassezia; among patients with head-and-neck dermatitis generally, 28% did.

Malassezia involvement is worth suspecting when eczema sits on the head and neck, when it flared in adolescence or young adulthood, and when it resists conventional treatment. In studies, antifungal treatment has helped adults with head-and-neck AD and positive Malassezia tests. Whether that applies to you, and what would be used, is entirely a specialist's judgement — the useful thing here is knowing the question exists.

The same yeast is behind seborrheic dermatitis, which is the other reason an adult's face may not be behaving like atopic eczema.

Where this sits

None of this means your eczema is secretly fungal. Most eczema is exactly what it appears to be. It means that "it isn't responding" is a reason to re-open the diagnosis, not only to escalate the treatment — and that is a legitimate thing to say out loud at an appointment. See is it eczema — or something else?

Make “it isn’t working” a fact, not a feeling

Re-opening a diagnosis usually starts with being able to show that treatment stopped helping and when. Ollowen ties what you used to what your skin did, week by week, so that conversation begins with a record instead of an impression.

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Sources

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