Can allergies or allergic reactions cause hair loss?

Have you ever had an itchy scalp that just won’t calm down? Maybe it feels red, swollen, or irritated after you use a new shampoo or spend time around pollen. For many people in San Jose—where seasonal allergies are super common—these reactions can be more than annoying. They may even cause hair loss.

Let’s talk about how allergies affect your scalp and what you can do to keep your hair healthy.

Can Allergies Really Cause Hair Loss?

Yes, they can. When your body reacts to something it doesn’t like—such as pollen, pet dander, certain foods, or hair products—it triggers inflammation. That irritation can affect your scalp and your hair follicles.

Here are the two main ways allergies may lead to hair loss:

1. Inflammation of the Scalp

When your scalp becomes red, swollen, or itchy, the hair follicles can become stressed.Stressed follicles may stop growing hair or enter the shedding phase too soon.

2. Excessive Scratching and Irritation

Allergies often make your scalp itch.Constant scratching can damage the follicles and pull hair out faster than it can grow.

Common Allergies That Can Cause Hair Loss

Several types of allergies may affect your hair, including:

• Seasonal allergies (pollen, trees, grass—big in the Bay Area!)

• Product allergies (shampoo, conditioner, dyes, gels, sprays)

• Food allergies

• Dust or mold allergies

• Contact allergies from ingredients like fragrances or preservatives

If you notice more shedding after using a new product or during allergy season, your scalp may be reacting.

Signs Your Hair Loss Might Be Allergy-Related

Watch for these common symptoms:

• Itchy or burning scalp

• Redness or swelling

• Flaky or dry patches

• More hair in the shower or brush

• Hair that breaks easily

• Sudden shedding after exposure to allergens

These signs usually appear quickly—often within hours or days of exposure.

How to Protect Your Hair and Scalp

If you think allergies are causing your hair loss, try these simple steps:

• Stop using any new hair products and switch back to what you know works

• Use gentle, fragrance-free shampoos

• Wash your hair more often during high-pollen days

• Avoid scratching, even when it’s hard

• Use cool water rinses to calm irritation

• Keep indoor air clean with filters

• Talk to a doctor or allergist if symptoms continue

• See a trichologist for a scalp evaluation

These steps can help reduce irritation and allow your hair to grow normally again.

When to See a Trichologist

A trichologist is trained in scalp and hair conditions. They can check whether your hair loss is due to allergies or another issue, like hormones, stress, scalp disorders, or hair care habits. A professional scalp analysis can give you clear answers and a plan to restore your hair’s health.

You Don’t Have to Handle Hair Loss Alone

Hair loss feels stressful, but you’re not alone—and support is available. At New Look Institute, we are experts on hair, scalp health, and the many causes of hair loss, including allergies. We use advanced trichology principles to understand your unique condition and help you find real, effective solutions. Contact us today to schedule your complimentary consultation and let us help you feel confident again.