My father has a wart under his right armpit for quite a long time. (He don't know how long it has been there but for several years already) The wart under his right armpit is not pain at all, not red not itchy. Recently, he discovered another wart under his left armpit. It is pain when he touches it, not itchy not red either. There's no pus. Is this a symptom of an underlying illness? Is checkup required now? Thanks doctor.