Rash on upper and lower arms

Several weeks ago I went to a friend's house to help her with a decorating project.  This friend has had a rash on her arms for many months that is extremely itchy, to the point that she has to get up in the middle of the night and put ice packs on it to reduce the itching.  There are sores involved, I suspect from scratching.  She has been to a dermatologist and the doctor doesn't know what it is.  They have even done biopsies.  While I was there I too started itching on my left arm.  I didn't see the rash then but now it covers my arms and I also am waking in the night and putting ice on the rash.  The rash consists of small red bumps, about 2 to 3 mm in diameter.  When I scratch some of them break open and form a sore.  Not all of them do so I am assuming the other bumps are not "mature".  I have tried hydrocortisone cream, neosporin (in case it could be bacterial), and antifungal cream.  Nothing is working.  I am at a loss as to what this is.  Her husband has no rash.  The only thing I can think of that we have in common is a tree we sat under in her back yard.  I don't know where else to turn.  Can't see a doctor until the end of October.

[Alan Rockoff, MD]

I hope you will forgive me, if I say that I think the only thing your friend transmitted to you is concern about itch.  I can't think of a contagious rash which would affect only the arms.  It sounds to me as though you (and perhaps your friend) are in an itch-scratch cycle.  I recommend you try to break it by: applying Sarna lotion (OTC) as often as needed for itch; applying Aquaphor ointment at bedtime; and doing your level best to NEVER scratch.  (Hard, but Sarna helps.)

You really can't see a doctor till October?  Surely there must be someone, or a cancellation . . .

Best.

Dr. Rockoff