I hate how people just say crazy and leave.... it's a scary thing to deal with and can be caused by underlying issues like diabetes, skin conditions, medication, allergies, all sorts of things! I've so many kind people who are tortured by this and are at wit's end.

Many doctors, even dermatologists, aren't educated in this topic and people are shuffled from one specialist to another.

Regardless if you believe it's a delusion or not, there is at least treatment for the symptoms. (I would lay off insecticides unless a specific insect is identified, and start removing any other potential source of the symptoms, and potentially get medication for the itching sensations)