PPD reaction

Has anyone ever had a reaction to a hair color? A few weeks ago I thought it was the Bigen hair color or the fact that I take Biotin and Msm, well now I know it the hair color. I got my roots done yesterday and noticed some itching but woke up this morning with a severely sowllen and itchy scalp. Its so bad I may have to go the emergency room.

Does the swollen scalp due to hair color damage the hair in any way?

I had used Bigen for years and never had a reaction. Then one time last year after using it, I had ITCHING for days. No soreness or redness, just crazy itching!

I used it again a few months after that and had no problem.

I also used Robert Craig, which also has PPD, and it seemed better and milder, I also like the color better. His jet black is more natural looking.

Well, I went to the dermatologist this morn, and was told I have seborrheic dermatitis. I was just convinced it was an allergic reaction as my scalp was and is swollen. Has anyone experienced a swollen scalp?