Mold Rash: Everything You Need to Know
Medically reviewed by Daniel More, MD
A mold rash is an allergic skin condition caused by mold exposure. It is common in people who are sensitive or allergic to mold.
Mold rashes can be hard to identify because they do not have unique features. An allergist or other healthcare provider can help you find the cause of a rash and whether it is linked to mold. This can help you get the treatment you need and relieve symptoms.
This article describes mold rash symptoms, causes, testing, and treatments. It also explains ways to reduce your risk of getting a mold rash.
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Symptoms of a Mold Rash
Mold produces microscopic seeds called spores that float through the air. The spores can grow on almost any surface in a damp or moist environment, either inside or outside. As a result, you are likely exposed to mold daily when inhaling spores or touching surfaces where they land or grow.
Reactions to mold depend on the degree to which you are sensitive to or allergic to mold. Like other allergies, this sensitivity varies widely by individual. Some people may not react to mold at all.
Allergic reactions to mold can be immediate or delayed, so it can be hard to identify mold as the source of a new rash or skin itching. In addition, a mold rash does not always have features that distinguish it from other rashes caused by allergies.
A mold rash, like other rashes related to allergies, can appear as any of the following types of skin rashes:
Reproduced with permission from ©DermNet NZ www.dermnetnz.org 2022
Intensely itchy skin that leads to a rash
Dry, scaly skin
Red rash (more obvious on lighter skin tones)
Dark brown, purple, or grayish areas of skin (more common on darker skin tones)
Swelling or inflammation
Scratch marks or raw skin from scratching
Bumps or blisters that ooze fluid and crust over
Reproduced with permission from ©DermNet NZ and ©Waikato District Health Board www.dermnetnz.org 2022.
Intensely itchy skin
Swollen, hot, and red skin
Dry, scaly skin that may crack
Tenderness at the rash site
Burning or stinging
Vesicles (small blisters that may pop and drain clear fluid)
DermNet / CC BY-NC-ND
Urticaria on legsRed, raised rash on people with lighter skin
Flesh-colored rash on people with darker skin
Smooth, raised welts that differ in size and shape
Appearance of new hives as old hives disappear
Other Symptoms of Mold Exposure
Symptoms of mold exposure vary by individual depending on your sensitivity to mold. Symptoms can also be immediate or delayed, with minor symptoms that worsen over time.
People who are sensitive to mold spores or have mold allergies typically develop symptoms of rhinitis (hay fever) that can include:
Sneezing
Irritation of your nose, mouth, or throat
Runny nose
Wheezing or coughing
Mucus (phlegm) in your throat (postnatal drip)
Red or itchy eyes
Red or itchy skin
Shortness of breath and/or chest tightness in people who have allergic asthma
Learn More: How to Manage Mold Allergy Symptoms Year-Round
What Causes a Mold Rash?
Like any allergic reaction, a mold rash is triggered by an overly sensitive immune system. If you are sensitive or allergic to mold, your immune system identifies mold as an allergen, triggering an allergic reaction that leads to a mold rash and other allergy symptoms.
Inhaling or touching mold spores can cause an allergic reaction. When your immune system recognizes that you have come in contact with mold, which it identifies as harmful, it makes an antibody called immunoglobulin E (IgE).
The production of IgE triggers the release of the compound histamine. Histamine opens blood vessels, constricts airways, and creates mucus to protect your body from the allergen. These inflammatory responses result in allergy symptoms such as coughing, wheezing, and/or a mold rash.
Molds are found in almost every environment year-round. They thrive in shady, damp areas. Outdoor sites include places where leaves and other vegetation are decomposing.
Indoors, mold can exist under sinks, in bathrooms and basements, and around leaky areas. Mold can also thrive in building materials like paper and wood products. They also grow in dust, carpets, and upholstery.
Diagnosing a Mold Rash
Diagnosing a mold rash involves determining whether you have a mold allergy. Since symptoms of a mold allergy are similar to many other conditions, diagnosing a mold allergy requires a visit to a healthcare provider such as an allergist or immunologist.
Your healthcare provider will likely use one or more of the following evaluations to determine whether you have a mold allergy.
A Complete Medical History and Physical Exam
Like other allergies, mold allergies can run in families. Taking a complete medical history can reveal whether you have a higher risk of being allergic to mold.
Many rashes have similar characteristics. A physical exam may reveal symptoms that indicate whether your rash may be linked to mold or another medical condition.
Blood Tests
Allergy blood tests use a sample of your blood to diagnose allergies. The tests measure levels of IgE antibodies, which your immune system releases in response to an allergen.
One drawback of this procedure is that results can take days since the process involves sending a sample to an offsite laboratory.
Skin Prick Test
A skin prick test is the most accurate way to diagnose an allergy. It can check for many types of allergies simultaneously and provides results in about 20 minutes.
The test involves placing droplets of mold allergens onto the surface of your skin with tiny punctures. If more than one allergen is being tested, they will be placed at different spots to observe separate reactions.
If you are allergic to any allergens, a small red bump, about the size of a mosquito bite, will develop at the puncture site within 15 to 20 minutes.
Learn More: How Do You Know If You Have Allergies?
How to Treat a Mold Rash
The first step in treating a mold rash is to remove yourself from the source of the mold and avoid further contact with it if the source can be identified.
Other treatments depend on the location and severity of your rash. Your healthcare provider can advise the most appropriate treatments based on your symptoms:
Medications
The following medications for nasal and other allergic symptoms may be used:
Antihistamines: Antihistamines treat allergy symptoms by blocking the effects of histamine. Over-the-counter (OTC) antihistamines can be delivered via pills, capsules, chewable tablets, liquids, nasal sprays, and eye drops.
Hydrocortisone cream: Hydrocortisone cream (1%) can relieve redness, itching, swelling, and rash discomfort. It works by activating natural substances in your skin to reduce inflammation, redness, and itching.
Nasal corticosteroids: Nasal corticosteroid sprays reduce swelling and mucus in your nasal passages. They can relieve sneezing, a runny nose, nasal congestion, and other allergy symptoms that may accompany a mold rash.
Antibiotics: A mold rash can become infected from scratching. Your healthcare provider may prescribe an oral antibiotic if your rash shows signs of an infection from persistent scratching.
Moisturizers: OTC moisturizers may help soothe dry, cracked, and itchy skin. Hypoallergenic and anti-itch moisturizers with the following ingredients can help relieve rashes:
Oat or shea butter
Petrolatum
Immunotherapy works by gradually exposing your body to an allergen to reduce the severity of an allergic reaction over time. The allergen can be administered through injection (allergy shots) or a sublingual (under the tongue) tablet.
It can take up to five years of treatment to build long-term resistance. However, lasting relief and a reduction in allergy symptoms are possible with immunotherapy even after treatment ends.
Research indicates that immunotherapy with mold extracts can reduce asthma symptoms and the need for medication in people who have allergic asthma. This type of therapy can also help you maintain lung function.
Home remedies
The following home remedies can help relieve topical symptoms of itchiness, inflammation, and discomfort:
Aloe vera: Applied alone, aloe vera is a natural skin treatment due to its anti-inflammatory, antimicrobial, and wound-healing properties.
Cold compresses: Apply a cold, wet cloth or ice pack to the itchy area for about 5 to 10 minutes.
Colloidal oatmeal bath: Take a colloidal oatmeal bath in lukewarm water to soothe itchiness and blisters.
Stress reduction: Research indicates that stress can make skin itch more.
Cotton fabrics: Loose-fitting, cotton clothing can prevent irritating dry, itchy skin.
What Are the Risks of Mold Exposure?
The risks of mold exposure include a variety of health complications, which can vary by individual. Reactions can occur immediately or as delayed symptoms that worsen over time. Symptoms that worsen in a damp, humid, or moldy environment can indicate a mold allergy.
If you are sensitive or allergic to mold, exposure puts you at a higher risk of the following reactions that are similar to other respiratory allergies:
Sneezing
Irritation of your nose, mouth, or throat
Runny nose
Nasal congestion
Wheezing or coughing
Mucus (phlegm) in your throat (postnatal drip)
Red or itchy eyes
Red or itchy skin
Chest tightness
Worsening asthma symptoms
Inflamed airways
You have a higher risk for health problems linked to mold exposure if you have any of the following conditions:
Compromised immune system (HIV/AIDS infection, organ transplant or chemotherapy patients)
Underlying lung disease
Chronic respiratory disease (chronic obstructive pulmonary disorder (COPD), asthma, emphysema)
Your reaction to mold exposure may be more intense if you are allergic to molds, have asthma, or are exposed to large amounts of mold, such as working in settings with high mold levels. Severe reactions to mold exposure can include:
Worsening asthma symptoms leading to allergic asthma
Fever
Shortness of breath
Hypersensitivity pneumonitis, or "farmer's lung," a lung disease due to too much exposure to the fungi found in feed and grain
Under certain conditions, some types of mold can produce secondary toxins called mycotoxins. Exposure to mycotoxins can increase your risk of more serious illness from mold exposure.
How to Prevent a Mold Rash
Preventing a mold rash can be challenging since mold is virtually everywhere and its microscopic spores can be impossible to see. However, you can take precautions to reduce your potential contact with mold and your chances of having an allergic reaction or other ill effects.
Follow these strategies to prevent a mold rash:
Limit your time outside when mold counts are high.
Don't allow leaves and piles of dead plant material to accumulate.
When doing yard work or gardening, wear an N95 mask, hat, sunglasses, and clothing that fully covers your skin.
Reduce dampness in your home to prevent mold and mildew buildup, with close attention to bathrooms, basements, and laundry areas.
Vent clothes dryers to the outside.
Remove any visible black mold by cleaning or disposing of the affected materials. For mold removal from hard surfaces, use soap and water, or a bleach solution of no more than one cup of household laundry bleach in a gallon of water.
Use central air-conditioning with a certified asthma and allergy-friendly filter to trap mold spores in your home.
Increase airflow in your home by opening doors, moving furniture away from walls, and using fans.
Repair leaks in plumbing, roofs, and roof gutters as soon as possible.
Use a dehumidifier indoors to lower humidity and keep humidity between 45% and 30%.
Remove or replace carpets and upholstery that have been wet or damaged by water or flooding immediately.
Summary
A mold rash occurs when your immune system regards mold as an allergen. The release of antibodies triggers allergy symptoms that can include coughing, wheezing, and a skin rash.
A mold rash and other symptoms of a mold allergy are similar to many other health issues. Knowing whether your skin rash is caused by mold requires a medical diagnosis. Finding the source of your symptoms can ensure you get the right treatment to manage your problem as soon as possible.
Avoiding mold can be hard since it exists outside and inside all year round. Taking steps to reduce mold in and around your house can help you avoid a mold rash if you are allergic.
Read the original article on Verywell Health.
