severe itching without a rash

My son is 17 years old and currently involved on his highschool wrestling team.  About four weeks ago, he kept complaining about consistent itching on his inner thighs. Four weeks later, as well as changing all bedding , laundry detergents, bath and shower soaps and all products I could think of that would cause this reaction, he is still itching all over now.It is keeping him up at night and if he does not take a benadryl he does not sleep.  There is not one mark on his body.  There is some redness in the area when he scratches but that is from scratching as it disappears once the itching stops.  I was up two hours last night trying to put him to sleep applying benadry spray as well as calamine lotion.  Finally I had to give him a benadryl to get him drousy enough to sleep. I have no clue what is causing this and my next step is the emergency room if I can not get him into his physician.  Has anyone heard of anything like this and no what it could be?  All the information I read last night scared me to death about liver disease of mal function of the liver and/or kidneys. Please help.

[allmymarbles]

He takes a Benadryl and goes to sleep. That suggests it may be an allergy. I have allergies. When I don't take an antihistamine I itch - not rash - ho hives - just an itch.

[Bhupinder Kaur, MD]

Hello,
I cannot confirm anything without examination but it can be contact dermatitis, allergy, sweat dermatitis, heat rash, insect or scabies bites, hives, eczema or viral rash. You can take over the counter antihistaminic like Benadryl or Claritin for itching. Application of calamine lotion is also soothing. If symptoms persist then please consult your doctor.

It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.