Skin diseases can be due to;
1) Autoimmune phenomenon.
2) Food allergies/Environmental allergies.
3) Intestinal Parasites
4) Emotional and psychological factors.
5) Medications/herbs.
You would need the following investigations to ascertain the cause;
A) a complete blood cell (CBC) count with differential, erythrocyte sedimentation rate (ESR) and/or C-reactive protein (CRP), liver enzymes, and thyrotropin (TSH).
B) Examination of the stool for ova and parasites.
C) Hepatitis B and C titers.
D) Serum cryoglobulin and complement assays.
E) Thyroid function testing and antithyroid microsomal and peroxidase antibody titers.
F) Allergy tests
G) Skin biopsy
I hope your symptoms resolve soon.
I would be happy to assist you further if you need more information.
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