The skin which forms the largest organ in the body is involved in many homeostatic functions like temperature regulation, Vitamin D synthesis and forms a mechanical barrier against pathogens. It is a site of expression of various normal and abnormal processes in the body. The role of vata, pitta and kapha dosha are important in determining the nature of skin. The excellence of the dhatu is also expressed as healthy skin or dhatusaaratha. Rasasaaratha is equivalent to twaksaaratha. The equivalence of rasa to twak is an important factor in deciding the route of medicine as internal or external in skin disorders.
Dr Uma Karthik (2025) studied this question.