Ay, red marks sa paa, totoo yan, nakita ko rin yan sa anak ko dati! Could be from tight socks or diaper marks na malalim lang, pero if it's persistent or may swelling pa, better to show your pedia para ma-rule out kung walang infection or allergy na involved, kasi minsan madaling lang ma-miss ang signs. One of my mum friends' baby had something similar and nag-clear lang after she switched to looser socks, pero mas safe talaga kung checked muna ng doctor lalo na kung new pa lang ang marks na yan.