In general contact eczema or a food intolerance would be the cause. Lack of sleep really would be unusual - I've never heard of it (though I'm not a medical person). I think slagging off your doc for making reasonable conclusions is unfair. Debugging ASM has got to be an utter picnic compared to troubleshooting humans in a short time-slot.
You're right, it is extremely unusual and I shouldn't be speaking in this way about my doctor. They do in fact do great work for the majority of cases.
