Hi Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern.
Red rash on forehead can be due to many reason
1. Rash due to bacterial infection of skin. This can also cause swelling of lymph nodes nearby.
2 Rashes due to
allergic reaction.
3
Psoriasis,
impetigo and eczema are few of the diseases that are known to produce rashes or skin eruption.
4
Fungal infection can also lead to rashes.
These are submandibular lymph nodes situated between jaw and ear.
Submandibular lymph nodes can become enlarged,tender or palpable in a number of conditions such as infections of head, neck,
sinuses, ears, eyes, scalp, pharynx. Less common cause is cancer.
Visit your physician, he would tell you that both problems are linked or not
Don't worry you would be fine.
Hoping your query is solved