. >> reporter: it may yonezawa wore a mask when going out.ce became swollen and her body temperature rose to 38 degrees. >> translator: i felt feverish and sick and had a terrible headache. i had to take some medicine and rest. >> reporter: now yonezawa uses a face shield instead of a mask. but even in the shade she can only wear it for an hour. yonezawa feels self-conscious about what people may think of her walking around without a mask. >> translator: it's difficult when i have to go to the bank or to the shops and there are signs stating that customers without masks will not be allowed. the looks of disapproval i get are so hard for me to bear. >> reporter: people with skin diseases are not the only ones suffering. from children with developmental disorders have sensory hypersensitivity and are unable to wear masks. the condition can affect all five senses and the feeling of touch may be interpreted as painin. scientists have only just started learning how developmental disorder results in sensory hypersensitivity. masakazu is currently r