Back of the neck long pimples can be caused by folliculitis, subcutaneous lipoma, swollen lymph nodes behind the neck and other diseases, need to be analyzed according to the symptoms. 1. Folliculitis: Folliculitis occurs in the head, face, neck, buttocks, armpits and other parts of the body, mainly caused by bacteria, fungi and other pathogens caused by hair follicle infection. When folliculitis occurs in the back of the neck, red papules can appear, accompanied by red, swollen, hot, painful inflammatory reaction. 2. Subcutaneous lipoma: Subcutaneous lipoma is a benign tumor originated from subcutaneous fat tissue, most commonly found in the neck, back, shoulder, breast and other parts of the body, patients may have single or multiple subcutaneous lumps, forming “lumps”, soft texture, can be pushed, usually no obvious self-conscious symptoms. 3. Enlargement of posterior cervical lymph nodes: it mostly appears after inflammatory reaction caused by infection, fungus, etc. Tumor, reactive hyperplasia and other factors can also lead to the increase in the volume of posterior cervical lymph nodes. If inflammation causes enlarged lymph nodes, they are usually soft in texture, with pressure pain, smooth surface and no adhesion. Enlarged lymph nodes caused by lymph node metastasis from malignant tumors are hard in texture and adherent to the surrounding tissues. There may be other reasons for the lumps on the back of the neck, so you should go to a regular hospital in time to see a professional doctor to determine the cause of the disease and take appropriate treatment according to the cause of the disease.