Can People Be Allergic to Cotton?

A true immune-mediated allergy to cotton fiber itself is extraordinarily rare. Decades of research into occupational cotton exposure have struggled to produce clear evidence that the cellulose in cotton triggers the kind of immediate allergic response people associate with, say, pollen or peanuts. Yet reactions to cotton clothing are real, common enough to send people to dermatologists, and genuinely miserable. The disconnect comes down to what is actually on the cotton rather than the cotton itself, and the distinction matters for anyone trying to figure out why a “100% cotton” shirt made their skin erupt.

Why Cotton Fiber Itself Almost Never Causes Allergies

Cotton is about 90 percent cellulose, a plant-based polymer that is chemically simple and biologically inert in ways that make it a poor trigger for the immune system. Most allergens are proteins, and raw cotton fiber contains very little protein. This is part of why cotton has been a default recommendation for people with sensitive skin for generations.

The strongest evidence that cotton fiber is not much of an allergen comes, paradoxically, from workers who spend years breathing it in. In a study of 41 workers with byssinosis, a lung condition caused by cotton dust exposure, researchers tested for allergic skin reactions to cotton antigens. Immediate reactions, the kind that indicate a classic allergy, were seldom observed. Delayed reactions were nearly always present, but delayed skin responses point toward a different immune pathway and are not the same thing as the rapid allergic reactions most people mean when they say “allergy.”¹ In other words, even among people with the heaviest cotton exposure imaginable, true IgE-mediated allergy to cotton was hard to find.

That does not mean no one has ever had an allergic response to a cotton protein. Case reports exist, and some individuals with highly reactive immune systems could plausibly develop sensitization. But when a dermatologist investigates a patient’s rash from a cotton garment, the cotton fiber itself is nearly always ruled out in favor of something applied to it during manufacturing.

Formaldehyde in Wrinkle-Free and Easy-Care Cotton

If you have ever pulled a new dress shirt out of its packaging and noticed a faintly chemical smell, you were probably detecting formaldehyde. Cotton wrinkles easily, and manufacturers treat it with formaldehyde-based resins to earn labels like “wrinkle-free,” “iron-free,” or “easy-care.” These resins cross-link the cellulose fibers to keep them smooth, but they also release free formaldehyde, which can sit against your skin all day.

Formaldehyde is one of the more common contact allergens in the general population. For people who are sensitized, even the small amounts released from treated clothing can trigger allergic contact dermatitis, an itchy, red, sometimes blistering rash that appears where the fabric touches the skin.² The rash often appears in high-friction or high-moisture zones: the neck, inner arms, waistband area, and under the bra line for women.

Washing the garment before wearing it helps. Formaldehyde is water-soluble, and laundering removes a meaningful amount of the residual chemical. But a single wash does not eliminate all of it. Research on formaldehyde content in textiles confirms that repeated washing progressively reduces levels, though some resin-treated fabrics continue releasing formaldehyde at lower concentrations through many wash cycles.³ If you react to new cotton clothing but not to well-worn pieces, formaldehyde is a leading suspect.

Reactive Dyes and Color as a Hidden Allergen

Cotton fiber is white. Every color you see on a cotton garment got there through chemistry, and certain dye classes are documented allergens. Reactive dyes, widely used on cotton and other cellulosic fibers because they bond tightly and resist fading, are a particular concern. They are called “reactive” because they form a covalent bond with the fiber, but during the dyeing process some unreacted dye remains in the fabric if rinsing is inadequate.

In one telling case, a patient developed allergic contact dermatitis from a dark, unwashed 100% cotton T-shirt. Patch testing confirmed sensitivity to six reactive dyes. The rash resolved when the garment was removed, and the patient found that the shirt had to be washed at least three times before it stopped provoking his skin.⁴ Dark and intensely colored fabrics carry more dye, which is why dermatologists sometimes advise patients with unexplained clothing-related dermatitis to try switching to lighter colors first.

Dye allergy can be tricky to pin down because patch test panels at most dermatology clinics do not routinely include textile dyes. A patient might test negative to the standard allergen series and be told they are not allergic to anything, when the real culprit simply was not on the test menu. Specialized textile dye series exist but are not universally available. If your rash pattern follows the shape of a garment and worsens with new, deeply dyed clothing, dye sensitivity is worth raising with your doctor specifically.

Flame Retardants on Cotton Fabric

Cotton is flammable, and certain products, from children’s sleepwear to industrial workwear, are treated with flame-retardant chemicals to meet safety regulations. These chemicals add another layer of potential skin irritants and allergens. In one case report, a painter who wore a flame-retardant-treated white cotton cap developed eczema on his forehead exactly where the cap contacted his skin. Patch testing confirmed sensitivity to the specific flame retardant used on the cotton, not to formaldehyde or the fabric itself.⁵

Fire-retardant clothing, often required in occupational settings like oil refining and electrical work, has also been linked to skin eruptions in larger groups. An investigation of workers wearing fire-retardant clothing found that the eruption was most likely a form of irritant contact dermatitis related to inadequate laundering procedures rather than true allergic sensitization.⁶ That distinction matters: irritant dermatitis results from direct chemical damage to the skin barrier, while allergic contact dermatitis requires prior immune sensitization. The treatment and prevention strategies differ. Proper laundering of flame-retardant workwear, using the detergent and cycle specified by the manufacturer, can often resolve irritant reactions without switching to a different fabric.

Cotton Dust and the Lungs

The allergic conversation around cotton is incomplete without mentioning byssinosis, an occupational lung disease that affects workers in cotton processing facilities. Byssinosis is not a skin problem. It is a respiratory condition caused by inhaling cotton dust over months to years, and it has been recognized for over a century. Symptoms include chest tightness, wheezing, and shortness of breath, classically worse on the first day back at work after a break, a pattern so distinctive it earned the nickname “Monday fever.”

A study of female cotton industry workers in India found that all measured respiratory parameters, including lung capacity and airflow measures, were significantly reduced compared to control subjects without cotton dust exposure. The decline worsened with increasing duration of exposure.⁷

Whether byssinosis is truly “allergic” remains debated. The mechanism seems to involve a combination of direct irritation, endotoxin exposure from bacteria on the raw cotton, and possibly some immune-mediated components. For the general public who wears cotton clothing rather than processing raw cotton bales, byssinosis is not a practical concern. But it illustrates a broader point about cotton: the raw agricultural product and the finished fabric your shirt is made of are chemically quite different things, because processing removes most of the biological material that could provoke immune reactions.

Metal Hardware on Cotton Garments

Sometimes the reaction has nothing to do with the fabric or its finish. Nickel, one of the most common contact allergens worldwide, shows up in buttons, snaps, rivets, and zippers on cotton jeans and other garments. A study examining blue-jean buttons found that about one in six pairs tested positive for nickel release. Applying a single coat of clear nail polish to the button surface blocked nickel release completely in all tested pairs, and two standard wash-and-dry cycles also eliminated detectable nickel from those same buttons.⁸

The pattern of a nickel reaction is usually distinctive: a round, itchy patch of redness or eczema right at the navel or waist where a metal button presses against the skin. People sometimes assume the jeans themselves are the problem, or that they have developed a cotton allergy, when the fix is as simple as coating the offending button. If you notice a localized reaction at a single point rather than wherever the fabric touches, check the hardware before blaming the textile.

Cotton and Atopic Dermatitis

For people with eczema, fabric choice becomes a daily calculation. Cotton is generally considered a safe option, but the evidence is more complicated than the standard advice suggests. A review of fabric selection for atopic dermatitis found that traditional cotton and silk fabrics have mixed evidence for actually improving symptoms and severity, though both have been shown to be generally safe, meaning they do not make things worse for most people.⁹

The same review noted that large-diameter wool fibers reliably provoke itching and irritation in eczema patients, while ultra-fine merino wool turned out to be non-irritating and potentially beneficial. Emerging specialty fabrics with silver or chitosan coatings showed promise for reducing both symptom severity and bacterial colonization on eczema-prone skin. For most people with eczema, cotton remains a reasonable baseline choice, but it is not uniquely therapeutic. If you are already wearing cotton and still flaring, the fabric itself is likely not the variable you need to change. Look instead at the finishes, dyes, and detergents involved.

Cottonseed Proteins and Nut Allergy Cross-Reactivity

This is an emerging area of research that has nothing to do with wearing cotton on your skin. Cottonseed, the seed of the cotton plant, contains storage proteins that share structural similarities with major allergens in peanuts and tree nuts. Laboratory analysis found that the vicilin and legumin proteins from glandless cottonseed were recognized by IgE antibodies from people with peanut and tree nut allergies. The cotton vicilin showed similarity to peanut vicilin, and the cotton legumin showed similarity to cashew nut legumin, among others.¹⁰

This matters because cottonseed oil and cottonseed protein are used in processed foods, and newer glandless cottonseed varieties are being developed specifically as a food protein source. Highly refined cottonseed oil, like most highly refined vegetable oils, has very little residual protein and is generally considered safe even for allergic individuals. But less refined products or novel cottonseed protein ingredients could theoretically pose a risk for people with peanut or tree nut allergies. This is an allergen risk assessment question for food regulators, not something that makes wearing a cotton shirt dangerous. The proteins in cottonseed are removed during fiber processing and are not present in the finished textile.

Does “Organic Cotton” Eliminate the Risk?

Organic cotton is grown without synthetic pesticides or fertilizers, which addresses concerns about agricultural chemical residues on the raw fiber. But organic certification speaks to how the cotton was farmed, not necessarily to what happens afterward. Dyeing, finishing, and chemical treatment are separate stages, and an organic cotton garment can still be treated with formaldehyde resins, reactive dyes, or other finishing agents.

A study analyzing chemical pollutants in clothing textiles found detectable levels of benzothiazole and related compounds even in garments made from certified organic cotton. One of the highest concentrations measured, at 22 micrograms per gram, came from an organic cotton baby garment carrying the Nordic Ecolabel certification.¹¹ This does not mean organic cotton is worse than conventional, but it does mean the “organic” label alone does not guarantee a chemically minimal product. For people trying to minimize skin reactions, certifications like OEKO-TEX Standard 100, which test the finished product for harmful substances rather than certifying the farming method, may be more relevant than organic labeling.

Chemical Concerns Specific to Infant Clothing

Parents often default to cotton for babies, and for good reason: it is soft, breathable, and historically well-tolerated. Research on infants wearing softened versus unsoftened cotton fabrics found no harmful effects on infant skin from either type. Skin hydration improved slightly with fabric-softener-treated cotton, and pH showed only a marginal difference between the two groups.¹²

The more pressing concern with infant cotton clothing involves chemicals the fabric absorbs from its environment. Cotton fibers readily adsorb phthalates, a class of plasticizers found widely in manufacturing environments. A study of infant cotton clothing collected from retail stores in China found high detection rates and concentrations of phthalates, and traditional laundering did not remove them completely. The researchers noted that dermal absorption had become the main exposure route for infants, and the levels of one particular phthalate, DEHP, were high enough to raise concern about potential adverse health effects.¹³ These are not allergy triggers in the classical sense, but they represent a health concern specific to cotton’s chemical absorbency and infants’ vulnerability.

Bisphenols in Recycled Cotton Blends

Recycled-content clothing has gained popularity as a sustainability choice, but the recycling process introduces its own chemical profile. A study comparing bisphenol levels in recycled versus conventional textiles found that the median concentration of bisphenol A (BPA) in recycled textiles was nearly twice that in conventional ones. Meanwhile, bisphenol S (BPS) showed higher median levels in conventional textiles, suggesting that manufacturers have been shifting from BPA to BPS, a substitution whose health implications are still being studied.¹⁴

Bisphenols are endocrine-disrupting compounds, not classical allergens. They do not cause the itchy rashes or respiratory symptoms associated with allergy. But their presence in textiles, including cotton blends, adds to the broader picture of what your clothing carries besides the fiber itself. For consumers choosing recycled textiles for environmental reasons, the tradeoff is worth knowing about, even if the dermal exposure levels from clothing remain well below those considered immediately harmful by most regulatory agencies. The science on low-level chronic bisphenol exposure through skin is still evolving.