Difficult to say without evaluation.
Certainly the constant itchy rash would warrant some form of allergy testing, including IgE testing for various antigents.
The tingling sensation in the fingertips may be caused by carpal tunnel or other nerve disorder/compression. A referral to a neurologist can be considered for electrodiagnostic testing.
Diarrhea can also have many causes. Infection should certainly be ruled out - but if it continues, a sigmoidoscopy can be done to evaluate for inflammatory bowel disease. If there is stress and anxiety present, you can consider irritable bowel syndrome as a possible diagnosis.
If the rash continues despite normal testing, you can consider a referral to a dermatologist. A skin biopsy can be considered to give a more definitive diagnosis.
These options can be discussed with your personal physician or in conjunction with a second opinion.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
http://www.straightfromthedoc.com
But your skin reactions, frequent infections, and neck and shoulder pain...are definitely hypothyroid symptoms. Doctors often miss this diagnosis in a person because the person doesn't fit the erroneous stereotype of older woman is who lazy and overweight. But I have seen that more frequently hypothyroidism presents as some type of cluster of assorted symptoms. My own case once just had skin disorder, asthma and sinus disorder, anxiety and digestive issues. Unfortunately, I was seeing 4 different docs for those conditions and so it took a while before I was able to get diagnosed. It took other symptoms appearing and increasing to a debilitating level. This is a problem in a culture that sees various specialists for their disorders.
So check it out. Ya just never know...