When there was a separate manifestation of skin, the controlling deities of sensations and their different parts entered into it, and thus the living entities feel itching and happiness due to touch.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
त्वचमस्य विनिर्भिन्नां विविशुर्धिष्ण्यमोषधीः । अंशेन रोमभिः कण्डूं यैरसौ प्रतिपद्यते
tvacamasya vinirbhinnāṃ viviśurdhiṣṇyamoṣadhīḥ | aṃśena romabhiḥ kaṇḍūṃ yairasau pratipadyate
SB 3.6.18