Charak Samhita
कण्डूः सन्धिषु रुग्भूत्वा भूत्वा नश्यति चासकृत् । वैवर्ण्यं मण्डलोत्पत्तिर्वातासृक्पूर्वलक्षणम् ॥१८॥
appearance of pain in the joints and abatement (without treatment), discoloration of body, appearance of mandala (circular skin lesions) are the premonitory symptoms of vatashonita.
english translation
kaNDUH sandhiSu rugbhUtvA bhUtvA nazyati cAsakRt । vaivarNyaM maNDalotpattirvAtAsRkpUrvalakSaNam ॥18॥
hk transliteration by Sanscript