Localised swellings below ear are likely to be lymph
nodes or minor enlargements of salivary glands. In your case, the doctor has examined it to be lymph node and prescribed ATT. You can get a documentary proof by getting FNAC or nodal biopsy
. However, if you have had a Chest X ray
which has supported TB, you may go ahead with ATT. Alternately, you can get tests for antibodies
to tubercular antigens in blood also.
Yes, TB is infectious and definitely needs treatment once diagnosed.