Hi and welcome to HCM
From your history, you have genetically
dry skin and prone to
eczema. Since your skin is on the drier side, each time you go to drier climate it will dry out the moisture in your skin further. This can cause your skin to crack , stretch and itch. Also exposes it more to dry wind, dust, pollen and other allergic factors since it loses its protective moisture.
You are also more prone to such allergies more than others, so whenever you experience such conditions, make sure to moisturize your skin very well, esp immediately after a shower before it completely dries out. Use a mild syndet based/glycerine soap. Apply an intensive moisturizer preferably without fragrances, suitable for sensitive skin.
When you have itching and rashes, apply a soothing lotion of
calamine with
aloe vera base and also antihistamines to help. If you have red rashes, peeling skin etc or an obvious
allergic reaction you can apply a
steroid cream for a few days only on the rash, such as
mometasone.
Cover yourself in comfortable clothes when outside to prevent exposure to allergens. Also keep a check if certain foods,etc make it worse.
This is a periodic condition, and since you are aware of the factors that make it worse, be prepared as advised if you cannot avoid it.
Hope this helps.