As cold and flu season finally wanes, a new danger lurking in the snow could be responsible for your runny nose and cough.
Multiple storms and blistering temperatures this winter season have left millions of Americans surrounded by snow that refuses to melt.
As the snow gradually dissipates, health experts warn the moisture creates a prime breeding ground for 'snow mold,' a fungal lawn disease that develops when snow covers grass during the winter.
Dr Farzana Hoque, associate professor of medicine at SSM Health Saint Louis University Hospital in Missouri, warned that the damp water from snow 'is creating an environment for growing these molds - all this fungus.'
While mold can be harmless for many, the National Institutes of Health (NIH) estimates anywhere from three to 10 percent of Americans have mold allergies, adding up to 10 to 33 million people.
Symptoms vary, but many of the signs can closely resemble the common cold or flu, including runny nose, congestion, sneezing, itchy eyes and coughing.
In severe cases, snow mold can trigger asthma attacks and respiratory infections like pneumonia.
Health experts warned that as temperatures gradually increase, melting snow creates extra moisture and can exacerbate the growth of mold.
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There are several types of mold that are more dangerous than others.
The most severe form, black mold, produces dangerous chemical compounds called mycotoxins that, when inhaled repeatedly, cause cognitive impairment, mood changes, asthma-like symptoms, headaches, coughs, muscle aches and autoimmune responses.
When the body detects toxins, such as spores in the air, the immune system launches a massive defense, sending out a storm of inflammatory chemicals called cytokines that act like emergency alarms.
Inflammatory cytokines can travel throughout the body via the bloodstream and reach every organ system, including the endocrine system and the brain. Mold then triggers inflammation, damages tissues and attacks vital cells and neurons.
Snow typically is a breeding ground for Microdochium patch, also called pink snow mold, and Typhula Blight, or gray snow mold.
Pink and gray snow mold can not only cause severe damage to grass but also allergic reactions in humans and pets due to the spores it releases.
Dogs allergic to mold may constantly scratch, bite or lick at their paws and skin or lose patches of their hair. They may also have a musty odor or dry, flaky skin.
Hoque told KSDK: 'If you are walking with your pet, make sure you are cleaning their paws before entering the home. If they're roaming around snowy or damp areas, it can easily be brought inside.'
Hoque also recommends that as temperatures rise and snow melts, creating more moisture, people spending time outdoors should change into fresh clothes before going inside.
She also suggests avoiding opening up windows until mold levels drop, which can be seen by looking at how quickly damage to grass has healed.
Gray snow mold typically only kills grass blades and resolves itself after raking and drying, while pink snow mold can kill roots and may need to be overseeded to prevent further damage.