Cladosporium Herbarum (Cla h 8) IgE Test · Blood

If you have eczema that flares on your face, neck, or scalp and refuses to settle no matter what cream you try, the cause may not be on your skin. It may be your immune system overreacting to a yeast that lives on almost everyone's skin: Malassezia sympodialis.

This blood test looks for IgE (immunoglobulin E) antibodies your body has built against a specific protein from that yeast, called Mala s 5. A positive result points to an allergic component in your skin disease that standard eczema care often misses entirely.

What This Test Actually Measures

Malassezia sympodialis is a yeast that normally lives on human skin without causing trouble. In some people with atopic dermatitis (the medical name for eczema), the immune system treats the yeast's proteins as threats and makes IgE antibodies against them. Mala s 5 is one of more than a dozen identified yeast proteins that can trigger this response.

The test reads out a single antibody, not the yeast itself. You may carry the yeast without making antibodies, or you may make antibodies even when your skin looks calm. The number reflects how strongly your immune system has been primed to react to this particular protein.

This is an emerging research-grade marker. There is no universal cutoff that defines a meaningful level, and reference ranges vary by laboratory. The most useful information comes from whether antibodies are present at all and how the result fits with your skin symptoms and other IgE testing.

Why It Matters for Adult Eczema

Sensitization to Malassezia is unusually concentrated in one group: adults with atopic dermatitis. In a study of 706 people, IgE against M. sympodialis showed up in 52 out of 97 atopic eczema patients. Among 571 people with other allergic diseases, only 4 tested positive. Healthy controls had none. That pattern makes this marker a relatively specific clue about eczema biology, not general allergy.

Earlier work using skin tests and serum IgE found that when people with atopic eczema do react to Malassezia, they often react to a small set of proteins including Mala s 1, 5, 6, and 9. So Mala s 5 sits inside a broader sensitization pattern, with Mala s 13 emerging as the most frequently recognized component in a detailed adult study where individual proteins were recognized in roughly 2 to 30 percent of patients.

Head and Neck Eczema

The clearest signal comes from eczema that concentrates above the shoulders. A meta-analysis pooling 14 studies found that about 79 percent of patients with head and neck atopic dermatitis carry IgE to Malassezia. Individual cohorts have reported positivity rates from about 49 percent to as high as 80 percent.

If your eczema is mainly on your face, scalp, or upper neck, the chance that a yeast-driven allergic loop is part of the story is meaningfully higher than for eczema elsewhere on the body. This is also one of the few situations where testing can change what your dermatologist actually prescribes, because antifungal treatments have shown clinical improvement in patients who test positive.

Eczema Severity

Across multiple adult cohorts, people with positive Malassezia IgE tend to have more severe disease than those without. In one study using a standardized severity score, the strength of the link between Malassezia-specific IgE and severity was moderate (a correlation of about 0.43). Total IgE, a separate marker of overall allergic tone, also tracks with severity.

What this means for you: a positive result does not just label your eczema as allergic. It suggests your case may sit in a more severe, more atopic phenotype, with multiple microbial and environmental triggers in play. That is useful context when deciding how aggressively to treat and what other allergens to test for.

Children and Infants

Sensitization to Malassezia is less common in children than in adults but is not rare. In a general pediatric eczema cohort, 17 percent tested positive, including infants as young as 4 months. In children with eczema combined with food allergy, 20 percent had IgE to M. sympodialis specifically and 27 percent to a broader Malassezia mix by age 11.

Greater eczema extent in infancy was a predictor of becoming sensitized to Malassezia a decade later. For a child with severe early eczema, this test can identify an additional layer of immune activity worth tracking as they grow.

Why a Single Result Is Not Enough

Allergic sensitization is dynamic. IgE levels shift with disease activity, treatment, and exposure. The research base does not yet provide a published intra-individual coefficient of variation for Mala s 5 IgE, which is part of why this remains an emerging marker rather than an established one with hard cutpoints.

A single positive or negative reading is best treated as one data point, not a verdict. Get a baseline now. If you are making changes to your skin care, starting an antifungal trial under a dermatologist's care, or beginning a systemic eczema treatment, retest in 3 to 6 months to see how the marker moves. Then retest at least annually if you are actively managing eczema, so you can watch the trajectory rather than chase a single number.

What to Do With an Unexpected Result

A positive result is most actionable when it lines up with your clinical picture. If you have face, scalp, or neck eczema and test positive, that combination is the strongest case in the literature for a Malassezia-driven trigger, and the one most likely to respond to antifungal-targeted strategies under a dermatologist's care.

If you test positive but have no skin symptoms, the result is harder to act on. Sensitization without disease has not been shown to predict future eczema or to benefit from preemptive treatment. Keep the result on file as part of your allergy profile and revisit if symptoms appear.

A negative result does not rule out a yeast-related contribution. Testing only M. sympodialis can miss roughly 20 percent of Malassezia-sensitized patients who react to other species in the same family. If your clinical picture strongly suggests yeast involvement and this test is negative, ask about broader Malassezia mix testing or component testing for other proteins like Mala s 13.

Companion Tests That Sharpen the Picture

This biomarker rarely stands alone. Total IgE provides a measure of your overall allergic tone, and the level often tracks with eczema severity. A broader aeroallergen and food IgE panel helps map your full sensitization profile, since polysensitization is common in more severe atopic dermatitis. Tests for other microbial triggers, particularly Staphylococcus aureus, can round out the picture of which organisms your immune system is engaging with on your skin.

When Results Can Be Misleading

A few points are worth knowing before you read your result:

• Single-species testing has blind spots: the Mala s 5 component is one piece of a complex sensitization pattern. A negative does not exclude reactions to related yeast species or other Malassezia proteins.
• This is not on standard allergy panels: generic aeroallergen and food panels do not automatically include Malassezia. A normal-looking standard allergy workup tells you nothing about this marker.
• Sensitization does not equal disease: a positive IgE means your immune system recognizes the yeast. Whether that recognition is actively driving your skin symptoms depends on your clinical picture, not the number alone.
• Recent biologic treatment can shift specific IgE: in observational data on adults with atopic dermatitis, dupilumab treatment lowered allergen-specific IgE over time. If you are on a biologic, interpret results with your prescriber.

Who Should Consider This Test

This test is most useful as a diagnostic adjunct, not a population screen. There is no evidence that testing asymptomatic adults improves outcomes or detects early disease. The reasonable cases for ordering it are clinical: you have atopic dermatitis that concentrates on your face, scalp, or neck, your eczema is moderate to severe and not fully responding to standard care, or you want to understand the microbial drivers of your skin disease before considering antifungal-targeted therapy with your dermatologist.