Mold Spores Allergy – Symptoms and Treatment

What is Mold?

Molds (in British English = moulds) are a type of multi-cellular fungi (as opposed to yeasts that are one-cell fungi). Molds are widely present in nature – they break down organic substances.

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Mildew is a type of fungi that appear on plants (outdoor and indoor). In practice, a term mildew is often used for any mold growth.

Mold Spores

Molds produce spores (a kind of microscopic seeds) that represent an inactive form of mold from which new molds may develop. There are usually mold spores that cause mold allergies, and not molds themselves.

Outdoor Molds

Common molds appearing outdoors are Alternaria, and Cladosporium. Outdoor mold spores appear in the air during and after:

  • Wind or Storm
  • Cutting grass
  • Spreading mulch
  • Harvesting

Indoor Molds

Common indoor molds are Aspergillus and Penicillium. Beside that, spores of outdoor molds may come into buildings through the air. Indoor mold spores commonly appear in the house dust. Any activity that raises dust from the floor may result in spores appearance in the indoor air, especially:

  • Dust vacuuming
  • Changing beds
  • Aerating the house

When spores land on moist indoor surfaces, like walls, furniture, carpets, paper, clothes, or food, they develop into active forms. These grow as white, yellow, green, reddish, grey, or black, smooth or furry patches.

What Are Mold Allergies?

In sensitive people, mold spores, when inhaled for the first time, trigger production of IgE antibodies in the eye conjunctiva, or nose, throat, or bronchial mucosa. During the subsequent inhalations of spores, IgE antibodies bind on mast cells in mucosa, and trigger release of a histamine from them. Histamine causes mucosal swelling and discharge, what in next minutes results in mold allergy symptoms:

  • Wet, itchy eyes
  • Sneezing, runny nose, cough
  • Chronic sinusitis
  • Wheezing, short breath (symptoms of asthma)

Symptoms in asthma may be quite severe, but deaths from mold allergy are extremely rare.

Diagnosis of Mold Allergy

Presence of allergy may be suspected from symptoms and positive blood tests, like increased amount of eosinophils (special type of white cells), and IgE antibodies.

Exact cause of allergy can be determined by skin tests, either by injecting of suspecting mold allergens into a skin, or by patch tests.

Treatment of Mold Allergy

Symptoms may be reduced with antihistamines by mouth taken after symptom appearance, or with other drugs prescribed by a doctor. In severe allergic reaction, that may appear in asthmatic child, injection or self-administration (by “epi-pen”) of adrenalin (epinephrine), is indicated.

In some cases, treatment of an allergy itself is possible with immunotherapy. Increasing amounts of allergens are injected into the blood over period of several weeks, what often helps to reduce symptoms of allergy.

Who is at Risk to Develop Mold Allergy?

Risk factors for developing mold allergy are:

  • Mold allergy in family. If one family member has a mold allergy, other family members are at increased risk to get it also.
  • Occupations with high exposure to mold: farming, baking, mill-work, carpentry, greenhouse work, wine-making, and furniture repair.
  • Living in a moist house. Molds readily thrive in houses with moistness above 50%.
  • Uncovered stored food. Molds may appear in few days on bread, fruits (in pastries, basements).

Prevention of Mold Allergy

To prevent mold allergy, a sensitive person should:

  • Avoid walking around when there’s a lot of mold spores in the air.
  • Avoid house dust that commonly contain mold spores. Spores can survive in a house dust for long periods, since they are highly resistant to low and high temperatures and pressure.
  • Prevent or eradicate mold in living environment. .

Other buildings commonly affected are stores, granaries, car washes, swimming pools, and other moist places.


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