I have dry,itchy pimples growing under my elbow. can it be from the cold weather.. what to do?

Possible: Dry skin can cause it. Try applying moisturizer at the area 2x daily especially after bathing. If not helpful after 2 weeks, see dermatologist. Cold weather is associated with dry air especially when the furnace is running, thus the increased problem with dry skin.

May need biopsy: This could be several skin diseases. Please see your dermatologist for an evaluation. You may need a biopsy to find out what is causing the bumps-.pimples.

Vaseline: very likely to be from the dry weather, applying a thick moisturizer such as Vaseline should help

Itchy bumps: Can be eczema and eczema is often worsened by cold weather. Try a 1% Hydrocortisone cream (OTC) as a first tx. if the condition does not improve , visit a Dermatologist.