If you live in a house with mold caused by high humidity, an allergic reaction can quickly start and lead to hair loss. During these allergic reactions, your immune system secretes a chemical called histamine. Histamine causes inflammation that disrupts blood flow in the capillaries that nourish the roots of your hair. This can lead to the hair not getting enough blood, and eventually, your hair can start to fall out. And be aware that allergies to mold can, in some cases, even lead to baldness.
In addition to mold spores, the allergens in the air inside a home that can cause hair loss are the excretions of mites, chemicals, and biological enzymes found in laundry powder.
If you find that you are starting to lose your hair due to a mold allergy, the first step is first to remove any mold from your home.