Hello,
The exact cause of seborrheic dermatitis is not properly understood and the prime cause is thought to be an yeast (
fungus) called Malassezia. Although it is a
fungus, but unlike other fungal infections, it is not contagious and is not considered an infection. Hence it is not transferred to the other people, towels, beddings etc.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided.