intense itching

what can be caues have had diarrha maybe dehydrated.but i have severe skin itching without rashes skin literaly burns even when i shower,intense increase of forearm,armpits,back of knees,inner thighs,goes away then returns in a month with no visible rash.PLEASE HELP IF YOU CAN

[Dr Santos]

Hi,

There are many causes of itching and may include any of the following:sunburn, hives, parasites, dry skin, allergic reactions, kidney disease, liver disease with jaundice, reactions to medications, pregnancy, hepatitis or iron deficiency anemia.
Are there other signs or symptoms present?  

Avoid scratching or rubbing the itchy areas. Wear cool, light, loose bedclothes. Take lukewarm baths using little soap and rinsing thoroughly. Cold compresses to an itchy area may also help. Over-the-counter oral antihistamines such as diphenhydramine may relieve the itching. It would be best to have this evaluated further by your doctor. Recurrent itching without obvious cause and  total body itching are all indications that the itching should be evaluated as soon as possible. Such itching may be a symptom of an underlying disease or possibly serious condition.

Take care and keep us posted.