SKIN REVIEW IN AYURVEDA

Skin is called ‘Twak’ which covers the whole body. The embryogenesis, anatomy and physiology of skin is finely defined in ayurvedic texts.Charak samhita has mentioned that ‘Twacha’ is the ‘updhatu’ of mamsa dhatu. According to Charak, when rakta dhatu gets digested its suksha prasadansha forms the mamsa dhatu along with sira and kandara as updhatus. This mamsa dhatu in the presence of mamsagni gets digested. Six types of twacha are fomed from its sukshma prasadansha and vasa (mamsagat sneh) is fomed as updhatu.
        In sushrut samhita it is described that bhootatma along with sukra and shonita when obtains maturation, then seven layers of skin are formed similarly as santanika is formed in milk layer by layer increasing in thickness.
        Skin is described under matraj bhav among the six bhavas in the production of foetus. The complexion, skin and nails appear during the sixth month of antenatal life. Bhel samhita says that ‘twacha’ is the location for ‘Oja’ and ‘Tej’ in the body.
Twach is said to be composed of all five elements which are Aakash, vayu, agni, Jal and pritvi as all the other substances of the universe.

Still vayu is the most predominant element in skin
Out of tridosh pitta is mainly considered as the inhabitant of Twach. ‘Bhrajak pitta’ is the type of pitta involved herein

ANATOMICAL DESCRIPTION OF TWACHA IN AYURVED


Twacha protects the body from varies physical and chemical stimuli present in the environment. It does so, by being a barrier between the body and the environment. It covers the whole body.

In ayurvedic text it is considered as an important ‘updhatu’. It is the updhatu of mamsa dhatu along with vasa. Updhatu is something which ‘bears’ (Dharan) the sharir. Twacha is also the adhisthan of sparshanendriya among the five indriyas.

Structually the skin is made up to six layers according to Acharya Charak and ashtang sangrah. But sushruta samhita and ashtang hridays counts seven layers of skin originating like santanika from milk, so there are certain controversies in Ayurvedic texts regarding the number of skin layers.
Charak samhita says that the sharir has six twacha, First one is 'prathama' or ‘udakdhara’ which is the outer most layer of skin, second is ‘Dwitiya’ or ‘Asrigdhara’ layer.

Third is the layer affected by diseases like sidma and kilas the fourth layer suffers from dadru and kushta. The fifth layer is the place for alaji and vidradhi. When the sixth layer is damaged it causes unconsciousness and darkness before eyes and is the place for black red colored, deeply embedded and difficult to treat arunshi.
These skins cover the whole shadang sharer.
Acharya sushruta says that there are seven layers of skin in sushrut sharir chapter four.

Description of skin layers according to sushrut samhita

S.No. Layer Thickness Disease

1. Avabhasini 1/18th of vreehi -Sidhma, padma kantak

2. Lohita 1/16th of vreehi -Tilkalak, nyachchh vrang.

3. Shweta 1/12th of vreehi -Charmadala, Ajgallika, mashak

4. Tamra 1/8th of vreehi -various types of kilas and kushtha

5. Vedini 1/5th of vreehi -Kushtha and visarpa

6. Rohini 1 of vreehi -Granthi, apachi, arbud, slipada, galgand

7. Mamsadhara 2 vreehi -Bhagandar, Visapa arsa

Ashtang samgrah says there are six layers of skin but has mentioned that other acharyas says that there are seven layers. Ashtang hriday has mentioned seven layers of skin.

Correlation of various types of skin with modern system-

1. Epidermis Avabhasini (udakdhara sharangstar)- Stratum corneum

                     Lohita (Swacchstar)-Stratum lucidum

                    Shweta (Kanmaya star)- Stratum granulosum

                   Tamra (Ranjak star) Stratum malpighii

2. Dermis- Vedini -Papillary layer

                  Rohini -Reticular layer

3. Hypodermis- Mamsadhara

KARMA

In Ayurvedic texts the main function of skin is ‘dharan’ as it is an updhatu. It covers the whole body and thus bears the body within it. Other karmas are -

 It protects the structures within the body

 It contains bhrajak pitta which maintains normal colour of skin it also imparts many assimilatory functions for lepa etc. its vitiation causes abnormal complexion. It depicts the chhaya and prabha of the body.

 Avabhasini layer is responsible for varna and chhaya of the body.

 It is the sparshanendriya adhishthan so is responsible for the tactile sensation in the body. This is due to the predominance of vayu mahabhut.

 The various wastes of the body are eliminated through the skin via the lomakupa present in addition sweda is an important vehicle for excretion which is eliminated through the skin. Atisweda or asweda causes many problems.

 It seems as a seat of attachment for mamsavah srotas and snayu.

Physiological concept of skin in Ayurveda

Crucial elements related to skin physiology in Ayurveda are –

Dosh siddhanta

This is a unique concept in Ayurveda.

 Vata prakriti – Thin, fine pored, darker complexion with whitish or greenish blue, cool to touch, especially in extremities and dry or rough and flaky in patches and climate sensitive.

 Vata vikriti – Lack of tone or luster, rough patches, chapping and cracking, dry rashes,corns and callouses, dry eczema.

 Pitta prakriti – Fair peachy, coppery or freckled complexion, soft lustrous and warm, chemically, sensitive, moist.

 Pitta vikriti – Rashes, inflammations, itching, premature wrinkling, yellow pustular acne, blackheads, whiteheads, general excessive oiliness, discoloration of natural pigment.

 Kapha prakriti – Thick moist pale, soft and cool to touch, generally tones well and light.

 Kapha vikriti – Dull sluggish, congested skin, enlarged pores, blackheads or large while pustules or cyst formation. Thick oily secretion.