The sensation of skin pain

The sensation of skin pain

It was commonly believed, for several centuries, that the body is all sensitive to pain.  It was not clear then that there were specialized nerves in the body responsible for transporting  all kinds of pain and other sensations, until recently when anatomy has discovered the role of specialized nerve endings in transporting all different kinds of pain.

The most significant nerve sensations in the human body are:  

• The sensation of touch: the corpuscles responsible for such sensation are called Meissners and Merkels corpuscles.

The sensation of pain: this is transported by the nerve endings in the skin.

The sensation of heat: this is the responsibility of Ruffini cylinders corpuscles.

The nerve endings will be exposed if the dermis and epidermis layers are injured
 

Taking skin burns as a distinct cause for the skin sensation of pain, burns can be divided into 3 types:

1-     Burns of first degree (sun burns): these affect the epidermis causing swelling and moderate pain.  The phenomena of redness, swelling and pain usually disappear within two to three days. (Figure 1).

2-     Burns of second degree: epidermis and dermis are injured.  In such a case, a detachment  occurs between epidermis and dermis, causing the collection of secretions between these two layers (Figure 2). The injured person suffers from severe pain, and excessive increase of pain sensation, due to irritation of exposed nerve ending particularly after the outburst of blisters.  The skin starts to heal within 14 days as a result of the process of renovation and inversion under the skin.

3-     Burns of third degree: the whole skin thickness is burned and perhaps the injury may reach the muscles or the bone.   The skin loses elasticity and becomes rough and dry.  In this case, the injured person do not feel much pain, as nerve endings have been damaged almost completely due to burning (Figure 3).

 

Burns of third degree (full thickness burn - not painful)	Burns of second degree (blister on the leg , very painful if outburst)	Burns of first degree (sun burn of the face)