Intercostobrachial nerve

The intercostobrachial nerve is a lateral cutaneous branch of the second intercostal nerve that supplies sensation to the skin of the axilla. It leaves the second intercostal space at the midaxillary line and subsequently pierces the serratus anterior muscle to enter the subcutaneous tissues of the axilla.

The nerve may be injured during axillary surgery such as nodal clearance for breast cancer .

Variant anatomy

• the lateral cutaneous branch of the third intercostal nerve may give rise to a second intercostobrachial nerve
• the intercostobrachial nerve may join the medial cutaneous nerve of the arm to supply the skin of the medial arm

Fun fact

Given it supplies the skin of the axilla, it is sometimes referred to as the 'tickle' nerve.