<s>[INST] I have had an allergic reaction to hair dye. I have taken antihistamine, It started off with 2 lumps 1 either side of the back of my neck. This morning I woke up with quite a large lump behind my ear and some throughout the bottom of my scalp. I am worried as they wasn t there this morning. What should I do and what could this be? Is it serious? [/INST] Hi, thanks for using Chat Doctor The lymph nodes are present in different points in the body. They respond to infection and inflammation present with the vicinity of their location. There are lymph nodes in the neck, in the area of the chin. They would have responded to the allergic reaction on your scalp. You can consider using anti-inflammatory painkillers such as ibuprofen, Catalan, aspirin or naproxen. In addition, the use of anti histamines would also be very helpful. This would include meds such as Benadryl, Allegra, Zyrtec, carnitine, Arius. I hope this helps </s>