Incredibly itchy rash without any redness

In the last week or so I have developed a mind numbingly itchy rash which presents as random slightly raised bumps with no surrounding redness or even unusual pigmentation outside of my skins natural hue.  It began localized to my upper arms and remains concentrated their but has begun to encroach on my forearms and has out postings of a few handfuls on my lower back, upper thighs and knees.  
I have had keratosis pilaris my whole life and have never been remotely bothered by it, being an extremely mild case.  I haven't added anything new to my skin care regime, nor my laundry detergents or diet.
Cortisone cream hasn't had much of an effect, in fact the only thing thus far to help has been a hot compress.
I have no idea what this is much less how to effectively cure it, having only been able to stem the tide at best thus far.

Any ideas?

[Bhupinder Kaur, MD]

Hello,
There are many possibilities for this itchy rash. It can be due to dermatitis, lice, scabies and hives or infected follicles of skin. Avoid using any lotions and creams for the meantime. Use a mild cleanser with moisturizing properties like Cetaphil. Also use cotton clothes and change the clothes twice if there is any increased sweating. Try keeping the skin free of sweat as far as possible. If the symptoms still persist then you can apply mild steroid like dermacort. For the itching antihistaminics like Benadryl or Claritin can be taken.

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.