Some causes of a swollen occipital lymph node are viral, bacterial or fungal infections. Swelling of the occipital lymph nodes can also be a symptom of cancer. The occipital lymph nodes are situated at the back of the skull near the neck area, notes Healthline.
Lymph nodes play an important role in the body's immune system, and they are found in different areas of the body, including the neck and head, states the National Institutes of Health's MedlinePlus. Occipital lymph nodes contain lymphocytes that can fight and kill foreign pathogens in the body.
The swelling of occipital lymph nodes, which is referred to as lymphadenopathy, can be linked to infections caused by viruses, bacteria or fungi. Medical conditions that can cause swelling are lice, seborrheic dermatitis, tinea capitis and secondary syphilis, according to Family Practice Notebook. Neoplasms and lymphoma are other possible causes of swollen lymph nodes in this region of the skull. Neoplasms are abnormal tissue growths that may be either benign or cancerous.