By Serena Solomon of RNZ Sneezing? Runny nose? Those symptoms are typically the same whether you are in the throes of seasonal allergies or a battle against a viral infection. Allergies are not contagious unlike a viral illness, which is contagious, making it hard to determine when to isolate from others to avoid spreading the infection. So, how do you know when it’s time to pop an antihistamine and soldier on to work or school, or raise a white flag and take a much-needed sick day ? It can be hard to tell.

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