) is usually caused by a viral or bacterial infection. Other causes include allergic reactions, arthritis, cancer, metabolic diseases, and an overactive thyroid (hyperthyroidism). In your case if the lymph nodes are swollen then dandruff alone cannot cause it and it is caused by fungal infection which can predispose to dandruff. My sincere advice would be to consult a dermatologist and get FNAC of the swollen lymph node done.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.