Have you looked into these two things?
Hypothyroidism is a common complaint of all dogs. The thyroid gland is unable to function and maintain adequate levels of the various hormones needed to keep the body systems functioning. The commonest reason for hypothyroidism is thought to be "auto-immune thyroiditis". This is when the dog's own immune system turns on the thyroid gland and systematically destroys it.
Symptoms of inadequate thyroid production are varied and range from hair loss (generally symmetrical and starting with the thighs and back legs), lethargy, weight increase and inability to keep warm. Diagnosis is done via a blood test which checks for various values of the different thyroid hormones, Michigan State is the main testing facility in the United States. Treatment is simple, a daily dose of synthetic thyroid is given to the dog. Care must be taken though in monitoring the dosage and thyroid panels do need to be run on a regular basis to make sure the correct dose is still being given. Again, thyroid supplementation is something that must be done with veterinary supervision.
As mentioned in the opening paragraph, mucin is the substance in Shar-pei skin that allows the wrinkling. For some unknown reason it can "bubble" up into the top layer of skin, forming clear blisters, generally under the the neck, on the flanks and/or on the hocks. These blisters can be broken open and will leak a sticky, clear fluid - mucin. No treatment is necessary for this condition and causes no problems. However, if the dog has other skin problems the dog can scratch the blisters open and a superficial skin infection can result. Keeping the area clean and dry will prevent infection and and treat these areas much as you would hot spots.