Dear Doctors, From the past few days, my father is having itchy sensation in back and back of the neck. After a lot of itching it becomes a small red-red pimple type. Here at our location humidity is much higher. He is saying it is happeneing due to heat and he applies nycil powder. But i feel it does not feel it happens due to heat. Small red bumps will become light black or light purple type. Is it something serious?. Will this happen due to heat?. Or due to some other reason. He is 62 years old, and he does not have any medical conidtion as of now.