Thank you for your inquiry.
Your patient, with a marked elevation of IgE, severe atopic dermatitis, and eosinophilia is not an uncommon presentation. However, in most patients, one finds no specific cause for this symptom complex, and treatment remains symptomatic. There is no specific mandated test that I would suggest for further workup. And, unfortunately, it is doubtful that allergen immunotherapy would be of much help in your patient. Your statement regarding the difficulty in establishing a cause for eosinophilia is well taken, and it is doubtful, as mentioned above, that you will find such a cause. I am afraid the treatment would be purely symptomatic for his eczema and atopic manifestations. Hopefully anti-IL5 will become available soon, and you might consider the use of this biologic agent.
In summary, I think you have done due diligence in your evaluation, and considering his economic circumstance, I would be prudent with further testing. I cannot think of any specific test that I would consider mandated at this point. I believe treatment should be the traditional therapy for his symptoms and if anti-IL5 becomes available, I would strongly consider, if financial circumstances allowed, the use of this agent.
Thank you again for your inquiry and we hope this response is helpful to you.
Phil Lieberman, M.D.