> However, one could very well imagine an infectious disease, with or without a dermatological component, causing delusional parasitosis.

Except what's more likely is that it's just psychological - which doesn't mean it doesn't have physiological treatments, it's just going to be for the psyche issue though.

Put it another way: it's well recognized eating disorders exist. But they're psychological disorders: they respond to psychological interventions and treatments, and are curable, but can also "spread" in viral like ways - i.e. an eating disorder can be induced by environmental (peer group) factors.

We don't generally posit that a virus spreads eating disorders, nor has any evidence of one been identified. And so in the same way, there's no reason to think Morgellons should have any underlying pathological cause that's any different, since none has been identified but we are aware of a number of psychological self-harm disorders (which can be amplified or spread sociologically but also just be unusual presentations of other conditions).