Supratrochlear nodes are one or two in number and located above the medial epicondyle of the humerus, medial to the basilic vein. [On the anteromedial aspect of the arm just above the elbow joint]
The afferents to supratrochlear lymph nodes drain the middle, ring, and little fingers, the medial portion of the hand, and the superficial area over the ulnar side of the forearm.
But as these vessels are in free communication with the other lymphatic vessels of the forearm, cross drainage is possible.
Their efferents vessels accompany the basilic vein and join the deeper vessels.
The supratrochlear lymph node gets enlarged in infections of hand and forearm and is frequently used in clinical diagnosis making. Palpation of supratrochlear lymph nodes is an important part of examination for lymphadenopathy.
Lymph nodes, in conjunction with the spleen, tonsils, adenoids, and Peyer patches, are highly organized centers of immune cells that filter antigen from the extracellular fluid.
The lymph node receives antigens that gain access through the skin or gastrointestinal tract.
Lymphadenopathy means lymph nodes which are abnormal in size (enlarged), number or consistency. Lymph nodes can enlarge due to infection, some autoimmune disease or malignancy.
How to Palpate Supratrochlear Lymph Nodes
1. Make the patient stand with back towards you. For an easier examination, the examiner may prefer to sit on a stool.
2. Expose the elbow and ask the patient to flex the elbow so that palm of his hand faces forward while upper limbs are lying on the side.
3. Grab the elbow from behind so that your thumb lies on the posterior aspect and your fingers rest on the anteromedial aspect of the elbow and inner of your hand encircles the lateral aspect of the elbow.
4. Start palpating a fingerbreadth above the elbow crease and feel for the lymph node.
The node is normally not palpable in otherwise healthy persons.